1
|
Kahsay A, Dennhag N, Liu JX, Nord H, Rönnbäck H, Thorell AE, von Hofsten J, Pedrosa Domellöf F. Obscurin Maintains Myofiber Identity in Extraocular Muscles. Invest Ophthalmol Vis Sci 2024; 65:19. [PMID: 38334702 PMCID: PMC10860686 DOI: 10.1167/iovs.65.2.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 01/12/2024] [Indexed: 02/10/2024] Open
Abstract
Purpose The cytoskeleton of the extraocular muscles (EOMs) is significantly different from that of other muscles. We aimed to investigate the role of obscurin, a fundamental cytoskeletal protein, in the EOMs. Methods The distribution of obscurin in human and zebrafish EOMs was compared using immunohistochemistry. The two obscurin genes in zebrafish, obscna and obscnb, were knocked out using CRISPR/Cas9, and the EOMs were investigated using immunohistochemistry, qPCR, and in situ hybridization. The optokinetic reflex (OKR) in five-day-old larvae and adult obscna-/-;obscnb-/- and sibling control zebrafish was analyzed. Swimming distance was recorded at the same age. Results The obscurin distribution pattern was similar in human and zebrafish EOMs. The proportion of slow and fast myofibers was reduced in obscna-/-;obscnb-/- zebrafish EOMs but not in trunk muscle, whereas the number of myofibers containing cardiac myosin myh7 was significantly increased in EOMs of obscurin double mutants. Loss of obscurin resulted in less OKRs in zebrafish larvae but not in adult zebrafish. Conclusions Obscurin expression is conserved in normal human and zebrafish EOMs. Loss of obscurin induces a myofiber type shift in the EOMs, with upregulation of cardiac myosin heavy chain, myh7, showing an adaptation strategy in EOMs. Our model will facilitate further studies in conditions related to obscurin.
Collapse
Affiliation(s)
- Abraha Kahsay
- Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden
| | - Nils Dennhag
- Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden
| | - Jing-Xia Liu
- Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
| | - Hanna Nord
- Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
| | - Hugo Rönnbäck
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden
| | | | - Jonas von Hofsten
- Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
| | - Fatima Pedrosa Domellöf
- Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden
| |
Collapse
|
2
|
Zemorshidi F, Töpf A, Claeys KG, McFarlane A, Patton A, Nafissi S, Straub V. Novel OBSCN variants associated with a risk to exercise-intolerance and rhabdomyolysis. Neuromuscul Disord 2024; 34:83-88. [PMID: 38159459 DOI: 10.1016/j.nmd.2023.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 10/16/2023] [Accepted: 10/23/2023] [Indexed: 01/03/2024]
Abstract
Obscurin, encoded by the OBSCN gene, is a muscle protein consisting of three main splice isoforms, obscurin-A, obscurin-B, and obscurin kinase-only protein (also known as KIAA1639 or Obsc-kin). Obscurin is located at the M-band and Z-disks and interacts with titin and myomesin. It plays an important role in the stability and maintenance of the A- and M-bands and the subsarcolemmal organization of the microtubule network. Furthermore, obscurin is involved in Ca2+ regulation and sarcoplasmic reticulum function and is connected to several other muscle proteins. OBSCN gene variants have been reported to be relatively common in inherited cardiomyopathies. Here we reported two young patients with a history of cramps, myalgia, exercise intolerance, rhabdomyolysis, and myoglobinuria without any evidence of concomitant cardiomyopathy in association with novel OBSCN variants (c.24822C>A and c.2653+1G>C). Obscurin-deficient muscle fibers seem to have increased susceptibility to damage triggered by exercise that may lead to rhabdomyolysis. More studies are needed to clarify the diverse clinical phenotypes and the pathophysiology of OBSCN gene variants.
Collapse
Affiliation(s)
- Fariba Zemorshidi
- Neuromuscular Research Center, Tehran University of Medical Sciences, Iran; Department of Neurology, Shariati Hospital,Tehran University of Medical Sciences, Tehran, Iran; Department of Neurology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Kristl G Claeys
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium; Laboratory for Muscle Diseases and Neuropathies, Department of Neurosciences, KU Leuven, and Leuven Brain Institute (LBI), Leuven, Belgium
| | - Adam McFarlane
- John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Annabel Patton
- John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Shahriar Nafissi
- Neuromuscular Research Center, Tehran University of Medical Sciences, Iran; Department of Neurology, Shariati Hospital,Tehran University of Medical Sciences, Tehran, Iran.
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
| |
Collapse
|
3
|
Pierantozzi E, Raucci L, Buonocore S, Rubino EM, Ding Q, Laurino A, Fiore F, Soldaini M, Chen J, Rossi D, Vangheluwe P, Chen H, Sorrentino V. Skeletal muscle overexpression of sAnk1.5 in transgenic mice does not predispose to type 2 diabetes. Sci Rep 2023; 13:8195. [PMID: 37210436 PMCID: PMC10199891 DOI: 10.1038/s41598-023-35393-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023] Open
Abstract
Genome-wide association studies (GWAS) and cis-expression quantitative trait locus (cis-eQTL) analyses indicated an association of the rs508419 single nucleotide polymorphism (SNP) with type 2 diabetes (T2D). rs508419 is localized in the muscle-specific internal promoter (P2) of the ANK1 gene, which drives the expression of the sAnk1.5 isoform. Functional studies showed that the rs508419 C/C variant results in increased transcriptional activity of the P2 promoter, leading to higher levels of sAnk1.5 mRNA and protein in skeletal muscle biopsies of individuals carrying the C/C genotype. To investigate whether sAnk1.5 overexpression in skeletal muscle might predispose to T2D development, we generated transgenic mice (TgsAnk1.5/+) in which the sAnk1.5 coding sequence was selectively overexpressed in skeletal muscle tissue. TgsAnk1.5/+ mice expressed up to 50% as much sAnk1.5 protein as wild-type (WT) muscles, mirroring the difference reported between individuals with the C/C or T/T genotype at rs508419. However, fasting glucose levels, glucose tolerance, insulin levels and insulin response in TgsAnk1.5/+ mice did not differ from those of age-matched WT mice monitored over a 12-month period. Even when fed a high-fat diet, TgsAnk1.5/+ mice only presented increased caloric intake, but glucose disposal, insulin tolerance and weight gain were comparable to those of WT mice fed a similar diet. Altogether, these data indicate that sAnk1.5 overexpression in skeletal muscle does not predispose mice to T2D susceptibility.
Collapse
Affiliation(s)
- E Pierantozzi
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - L Raucci
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - S Buonocore
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - E M Rubino
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - Q Ding
- Department of Cardio-Thoracic Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
| | - A Laurino
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - F Fiore
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - M Soldaini
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - J Chen
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, Katholieke Universiteit Leuven (KU Leuven), 3000, Leuven, Belgium
| | - D Rossi
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
- Interdepartmental Program of Molecular Diagnosis and Pathogenetic Mechanisms of Rare Genetic Diseases, Azienda Ospedaliera Universitaria Senese, 53100, Siena, Italy
| | - P Vangheluwe
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, Katholieke Universiteit Leuven (KU Leuven), 3000, Leuven, Belgium
| | - H Chen
- Department of Cardio-Thoracic Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
- Programme in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - V Sorrentino
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy.
- Interdepartmental Program of Molecular Diagnosis and Pathogenetic Mechanisms of Rare Genetic Diseases, Azienda Ospedaliera Universitaria Senese, 53100, Siena, Italy.
| |
Collapse
|
4
|
Koch D, Kho AL, Fukuzawa A, Alexandrovich A, Vanaanen KJ, Beavil A, Pfuhl M, Rees M, Gautel M. Obscurin Rho GEF domains are phosphorylated by MST-family kinases but do not exhibit nucleotide exchange factor activity towards Rho GTPases in vitro. PLoS One 2023; 18:e0284453. [PMID: 37079638 PMCID: PMC10118190 DOI: 10.1371/journal.pone.0284453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 04/01/2023] [Indexed: 04/21/2023] Open
Abstract
Obscurin is a giant muscle protein (>800 kDa) featuring multiple signalling domains, including an SH3-DH-PH domain triplet from the Trio-subfamily of guanosine nucleotide exchange factors (GEFs). While previous research suggests that these domains can activate the small GTPases RhoA and RhoQ in cells, in vitro characterization of these interactions using biophysical techniques has been hampered by the intrinsic instability of obscurin GEF domains. To study substrate specificity, mechanism and regulation of obscurin GEF function by individual domains, we successfully optimized recombinant production of obscurin GEF domains and found that MST-family kinases phosphorylate the obscurin DH domain at Thr5798. Despite extensive testing of multiple GEF domain fragments, we did not detect any nucleotide exchange activity in vitro against 9 representative small GTPases. Bioinformatic analyses show that obscurin differs from other Trio-subfamily GEFs in several important aspects. While further research is necessary to evaluate obscurin GEF activity in vivo, our results indicate that obscurin has atypical GEF domains that, if catalytically active at all, are subject to complex regulation.
Collapse
Affiliation(s)
- Daniel Koch
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Atsushi Fukuzawa
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Alexander Alexandrovich
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Kutti J. Vanaanen
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Andrew Beavil
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Mark Pfuhl
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Martin Rees
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| |
Collapse
|
5
|
Grogan A, Huang W, Brong A, Kane MA, Kontrogianni-Konstantopoulos A. Alterations in cytoskeletal and Ca 2+ cycling regulators in atria lacking the obscurin Ig58/59 module. Front Cardiovasc Med 2023; 10:1085840. [PMID: 37304957 PMCID: PMC10251194 DOI: 10.3389/fcvm.2023.1085840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/26/2023] [Indexed: 06/13/2023] Open
Abstract
Introduction Obscurin (720-870 kDa) is a giant cytoskeletal and signaling protein that possesses both structural and regulatory functions in striated muscles. Immunoglobulin domains 58/59 (Ig58/59) of obscurin bind to a diverse set of proteins that are essential for the proper structure and function of the heart, including giant titin, novex-3, and phospholamban (PLN). Importantly, the pathophysiological significance of the Ig58/59 module has been further underscored by the discovery of several mutations within Ig58/59 that are linked to various forms of myopathy in humans. We previously generated a constitutive deletion mouse model, Obscn-ΔIg58/59, that expresses obscurin lacking Ig58/59, and characterized the effects of this deletion on cardiac morphology and function through aging. Our findings demonstrated that Obscn-ΔIg58/59 male animals develop severe arrhythmia, primarily manifesting as episodes of junctional escape and spontaneous loss of regular p-waves, reminiscent of human atrial fibrillation, accompanied by significant atrial enlargement that progresses in severity with aging. Methods and Results To comprehensively characterize the molecular alterations responsible for these pathologies, we performed proteomic and phospho-proteomic analyses in aging Obscn-ΔIg58/59 atria. Our studies revealed extensive and novel alterations in the expression and phosphorylation profile of major cytoskeletal proteins, Ca2+ regulators, and Z-disk associated protein complexes in the Obscn-ΔIg58/59 atria through aging. Discussion These studies implicate obscurin, particularly the Ig58/59 module, as an essential regulator of the Z-disk associated cytoskeleton and Ca2+ cycling in the atria and provide new molecular insights into the development of atrial fibrillation and remodeling.
Collapse
Affiliation(s)
- Alyssa Grogan
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, MD, United States
| | - Weiliang Huang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States
| | - Annie Brong
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, MD, United States
| | - Maureen A. Kane
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States
| | | |
Collapse
|
6
|
Noureddine M, Gehmlich K. Structural and signaling proteins in the Z-disk and their role in cardiomyopathies. Front Physiol 2023; 14:1143858. [PMID: 36935760 PMCID: PMC10017460 DOI: 10.3389/fphys.2023.1143858] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/21/2023] [Indexed: 03/06/2023] Open
Abstract
The sarcomere is the smallest functional unit of muscle contraction. It is delineated by a protein-rich structure known as the Z-disk, alternating with M-bands. The Z-disk anchors the actin-rich thin filaments and plays a crucial role in maintaining the mechanical stability of the cardiac muscle. A multitude of proteins interact with each other at the Z-disk and they regulate the mechanical properties of the thin filaments. Over the past 2 decades, the role of the Z-disk in cardiac muscle contraction has been assessed widely, however, the impact of genetic variants in Z-disk proteins has still not been fully elucidated. This review discusses the various Z-disk proteins (alpha-actinin, filamin C, titin, muscle LIM protein, telethonin, myopalladin, nebulette, and nexilin) and Z-disk-associated proteins (desmin, and obscurin) and their role in cardiac structural stability and intracellular signaling. This review further explores how genetic variants of Z-disk proteins are linked to inherited cardiac conditions termed cardiomyopathies.
Collapse
Affiliation(s)
- Maya Noureddine
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- *Correspondence: Maya Noureddine, ; Katja Gehmlich,
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, United Kingdom
- *Correspondence: Maya Noureddine, ; Katja Gehmlich,
| |
Collapse
|
7
|
Gritsyna YV, Grabarskaya MA, Mikhailova GZ, Popova SS, Bobyleva LG, Ermakov AM, Zakharova NM, Vikhlyantsev IM. Differential Expression of Titin and Obscurin mRNA in Striated Muscles of the Long-Tailed Ground Squirrel Urocitellus undulatus. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022050052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
8
|
Subramaniam J, Yamankurt G, Cunha SR. Obscurin regulates ankyrin macromolecular complex formation. J Mol Cell Cardiol 2022; 168:44-57. [PMID: 35447147 PMCID: PMC11057898 DOI: 10.1016/j.yjmcc.2022.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 03/28/2022] [Accepted: 04/12/2022] [Indexed: 10/18/2022]
Abstract
Obscurin is a large scaffolding protein in striated muscle that maintains sarcolemmal integrity and aligns the sarcoplasmic reticulum with the underlying contractile machinery. Ankyrins are a family of adaptor proteins with some isoforms that interact with obscurin. Previous studies have examined obscurin interacting with individual ankyrins. In this study, we demonstrate that two different ankyrins interact with obscurin's carboxyl terminus via independent ankyrin-binding domains (ABDs). Using in-vitro binding assays, co-precipitation assays, and FLIM-FRET analysis, we show that obscurin interacts with small ankyrin 1.5 (sAnk1.5) and the muscle-specific ankyrin-G isoform (AnkG107). While there is no direct interaction between sAnk1.5 and AnkG107, obscurin connects the two ankyrins both in vitro and in cells. Moreover, AnkG107 recruits β-spectrin to this macromolecular protein complex and mutating obscurin's ABDs disrupts complex formation. To further characterize AnkG107 interaction with obscurin, we measure obscurin-binding to different AnkG107 isoforms expressed in the heart and find that the first obscurin-binding domain in AnkG107 principally mediates this interaction. We also find that AnkG107 does not bind to filamin-C and displays minimal binding to plectin-1 compared to obscurin. Finally, both sAnk1.5-GFP and AnkG107-CTD-RFP are targeted to the M-lines of ventricular cardiomyocytes and mutating their obscurin-binding domains disrupts the M-line localization of these ankyrin constructs. Altogether, these findings support a model in which obscurin can interact via independent binding domains with two different ankyrin protein complexes to target them to the sarcomeric M-line of ventricular cardiomyocytes.
Collapse
Affiliation(s)
- Janani Subramaniam
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, United States of America
| | - Gokay Yamankurt
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, United States of America
| | - Shane R Cunha
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, United States of America.
| |
Collapse
|
9
|
Rossi D, Pierantozzi E, Amadsun DO, Buonocore S, Rubino EM, Sorrentino V. The Sarcoplasmic Reticulum of Skeletal Muscle Cells: A Labyrinth of Membrane Contact Sites. Biomolecules 2022; 12:488. [PMID: 35454077 PMCID: PMC9026860 DOI: 10.3390/biom12040488] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/14/2022] [Accepted: 03/18/2022] [Indexed: 12/17/2022] Open
Abstract
The sarcoplasmic reticulum of skeletal muscle cells is a highly ordered structure consisting of an intricate network of tubules and cisternae specialized for regulating Ca2+ homeostasis in the context of muscle contraction. The sarcoplasmic reticulum contains several proteins, some of which support Ca2+ storage and release, while others regulate the formation and maintenance of this highly convoluted organelle and mediate the interaction with other components of the muscle fiber. In this review, some of the main issues concerning the biology of the sarcoplasmic reticulum will be described and discussed; particular attention will be addressed to the structure and function of the two domains of the sarcoplasmic reticulum supporting the excitation-contraction coupling and Ca2+-uptake mechanisms.
Collapse
Affiliation(s)
- Daniela Rossi
- Department of Molecular and Developmental Medicine, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (E.P.); (D.O.A.); (S.B.); (E.M.R.); (V.S.)
| | | | | | | | | | | |
Collapse
|
10
|
Bang ML, Bogomolovas J, Chen J. Understanding the molecular basis of cardiomyopathy. Am J Physiol Heart Circ Physiol 2022; 322:H181-H233. [PMID: 34797172 PMCID: PMC8759964 DOI: 10.1152/ajpheart.00562.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/16/2021] [Accepted: 11/16/2021] [Indexed: 02/03/2023]
Abstract
Inherited cardiomyopathies are a major cause of mortality and morbidity worldwide and can be caused by mutations in a wide range of proteins located in different cellular compartments. The present review is based on Dr. Ju Chen's 2021 Robert M. Berne Distinguished Lectureship of the American Physiological Society Cardiovascular Section, in which he provided an overview of the current knowledge on the cardiomyopathy-associated proteins that have been studied in his laboratory. The review provides a general summary of the proteins in different compartments of cardiomyocytes associated with cardiomyopathies, with specific focus on the proteins that have been studied in Dr. Chen's laboratory.
Collapse
Affiliation(s)
- Marie-Louise Bang
- Institute of Genetic and Biomedical Research (IRGB), National Research Council (CNR), Milan Unit, Milan, Italy
- IRCCS Humanitas Research Hospital, Rozzano (Milan), Italy
| | - Julius Bogomolovas
- Division of Cardiovascular Medicine, Department of Medicine Cardiology, University of California, San Diego, La Jolla, California
| | - Ju Chen
- Division of Cardiovascular Medicine, Department of Medicine Cardiology, University of California, San Diego, La Jolla, California
| |
Collapse
|
11
|
Pierantozzi E, Szentesi P, Paolini C, Dienes B, Fodor J, Oláh T, Colombini B, Rassier DE, Rubino EM, Lange S, Rossi D, Csernoch L, Bagni MA, Reggiani C, Sorrentino V. Impaired Intracellular Ca 2+ Dynamics, M-Band and Sarcomere Fragility in Skeletal Muscles of Obscurin KO Mice. Int J Mol Sci 2022; 23:1319. [PMID: 35163243 PMCID: PMC8835721 DOI: 10.3390/ijms23031319] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 12/16/2022] Open
Abstract
Obscurin is a giant sarcomeric protein expressed in striated muscles known to establish several interactions with other proteins of the sarcomere, but also with proteins of the sarcoplasmic reticulum and costameres. Here, we report experiments aiming to better understand the contribution of obscurin to skeletal muscle fibers, starting with a detailed characterization of the diaphragm muscle function, which we previously reported to be the most affected muscle in obscurin (Obscn) KO mice. Twitch and tetanus tension were not significantly different in the diaphragm of WT and Obscn KO mice, while the time to peak (TTP) and half relaxation time (HRT) were prolonged. Differences in force-frequency and force-velocity relationships and an enhanced fatigability are observed in an Obscn KO diaphragm with respect to WT controls. Voltage clamp experiments show that a sarcoplasmic reticulum's Ca2+ release and SERCA reuptake rates were decreased in muscle fibers from Obscn KO mice, suggesting that an impairment in intracellular Ca2+ dynamics could explain the observed differences in the TTP and HRT in the diaphragm. In partial contrast with previous observations, Obscn KO mice show a normal exercise tolerance, but fiber damage, the altered sarcomere ultrastructure and M-band disarray are still observed after intense exercise.
Collapse
Affiliation(s)
- Enrico Pierantozzi
- Department of Molecular and Developmental Medicine, Molecular Medicine Section, University of Siena, 53100 Siena, Italy; (E.P.); (E.M.R.); (D.R.)
| | - Péter Szentesi
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4002 Debrecen, Hungary; (P.S.); (B.D.); (J.F.); (T.O.); (L.C.)
| | - Cecilia Paolini
- Department of Neuroscience, Imaging and Clinical Sciences, University Gabriele d’ Annunzio of Chieti, 66100 Chieti, Italy;
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4002 Debrecen, Hungary; (P.S.); (B.D.); (J.F.); (T.O.); (L.C.)
| | - János Fodor
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4002 Debrecen, Hungary; (P.S.); (B.D.); (J.F.); (T.O.); (L.C.)
| | - Tamás Oláh
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4002 Debrecen, Hungary; (P.S.); (B.D.); (J.F.); (T.O.); (L.C.)
| | - Barbara Colombini
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy; (B.C.); (M.A.B.)
| | - Dilson E. Rassier
- Department of Kinesiology and Physical Education, McGill University, Montreal, QC H2W 1S4, Canada;
| | - Egidio Maria Rubino
- Department of Molecular and Developmental Medicine, Molecular Medicine Section, University of Siena, 53100 Siena, Italy; (E.P.); (E.M.R.); (D.R.)
| | - Stephan Lange
- Biomedical Research Facility 2, School of Medicine, University of California, La Jolla, CA 92093, USA;
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, 413 45 Gothenburg, Sweden
| | - Daniela Rossi
- Department of Molecular and Developmental Medicine, Molecular Medicine Section, University of Siena, 53100 Siena, Italy; (E.P.); (E.M.R.); (D.R.)
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4002 Debrecen, Hungary; (P.S.); (B.D.); (J.F.); (T.O.); (L.C.)
| | - Maria Angela Bagni
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy; (B.C.); (M.A.B.)
| | - Carlo Reggiani
- Department of Biomedical Science, University of Padova, 35121 Padova, Italy;
- Science and Research Center Koper, Institute for Kinesiology Research, 6000 Koper, Slovenia
| | - Vincenzo Sorrentino
- Department of Molecular and Developmental Medicine, Molecular Medicine Section, University of Siena, 53100 Siena, Italy; (E.P.); (E.M.R.); (D.R.)
| |
Collapse
|
12
|
Bogan JS. Ubiquitin-like processing of TUG proteins as a mechanism to regulate glucose uptake and energy metabolism in fat and muscle. Front Endocrinol (Lausanne) 2022; 13:1019405. [PMID: 36246906 PMCID: PMC9556833 DOI: 10.3389/fendo.2022.1019405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/06/2022] [Indexed: 12/02/2022] Open
Abstract
In response to insulin stimulation, fat and muscle cells mobilize GLUT4 glucose transporters to the cell surface to enhance glucose uptake. Ubiquitin-like processing of TUG (Aspscr1, UBXD9) proteins is a central mechanism to regulate this process. Here, recent advances in this area are reviewed. The data support a model in which intact TUG traps insulin-responsive "GLUT4 storage vesicles" at the Golgi matrix by binding vesicle cargoes with its N-terminus and matrix proteins with its C-terminus. Insulin stimulation liberates these vesicles by triggering endoproteolytic cleavage of TUG, mediated by the Usp25m protease. Cleavage occurs in fat and muscle cells, but not in fibroblasts or other cell types. Proteolytic processing of intact TUG generates TUGUL, a ubiquitin-like protein modifier, as the N-terminal cleavage product. In adipocytes, TUGUL modifies a single protein, the KIF5B kinesin motor, which carries GLUT4 and other vesicle cargoes to the cell surface. In muscle, this or another motor may be modified. After cleavage of intact TUG, the TUG C-terminal product is extracted from the Golgi matrix by the p97 (VCP) ATPase. In both muscle and fat, this cleavage product enters the nucleus, binds PPARγ and PGC-1α, and regulates gene expression to promote fatty acid oxidation and thermogenesis. The stability of the TUG C-terminal product is regulated by an Ate1 arginyltransferase-dependent N-degron pathway, which may create a feedback mechanism to control oxidative metabolism. Although it is now clear that TUG processing coordinates glucose uptake with other aspects of physiology and metabolism, many questions remain about how this pathway is regulated and how it is altered in metabolic disease in humans.
Collapse
Affiliation(s)
- Jonathan S. Bogan
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, United States
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, United States
- Yale Center for Molecular and Systems Metabolism, Yale School of Medicine, New Haven, CT, United States
- *Correspondence: Jonathan S. Bogan,
| |
Collapse
|
13
|
Cabrera-Serrano M, Caccavelli L, Savarese M, Vihola A, Jokela M, Johari M, Capiod T, Madrange M, Bugiardini E, Brady S, Quinlivan R, Merve A, Scalco R, Hilton-Jones D, Houlden H, Ibrahim Aydin H, Ceylaner S, Vockley J, Taylor RL, Folland C, Kelly A, Goullee H, Ylikallio E, Auranen M, Tyynismaa H, Udd B, Forrest ARR, Davis MR, Bratkovic D, Manton N, Robertson T, McCombe P, Laing NG, Phillips L, de Lonlay P, Ravenscroft G. Bi-allelic loss-of-function OBSCN variants predispose individuals to severe recurrent rhabdomyolysis. Brain 2021; 145:3985-3998. [DOI: 10.1093/brain/awab484] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 12/04/2021] [Accepted: 12/10/2021] [Indexed: 11/14/2022] Open
Abstract
Abstract
Rhabdomyolysis is the acute breakdown of skeletal myofibres in response to an initiating factor, most commonly toxins and over exertion. A variety of genetic disorders predispose to rhabdomyolysis through different pathogenic mechanisms, particularly in patients with recurrent episodes. However, most cases remain without a genetic diagnosis. Here we present six patients who presented with severe and recurrent rhabdomyolysis, usually with onset in the teenage years; other features included a history of myalgia and muscle cramps. We identified ten bi-allelic loss-of-function variants in the gene encoding obscurin (OBSCN) predisposing individuals to recurrent rhabdomyolysis. We show reduced expression of OBSCN and loss of obscurin protein in patient muscle. Obscurin is proposed to be involved in SR function and Ca2+ handling. Patient cultured myoblasts appear more susceptible to starvation as evidenced by a greater decreased in SR Ca2+ content compared to control myoblasts. This likely reflects a lower efficiency when pumping Ca2+ back into the SR and/or a decrease in Ca2+ SR storage ability when metabolism is diminished. OSBCN variants have previously been associated with cardiomyopathies. None of the patients presented with a cardiomyopathy and cardiac examinations were normal in all cases in which cardiac function was assessed. There was also no history of cardiomyopathy in first degree relatives, in particular in any of the carrier parents. This cohort is relatively young, thus follow-up studies and the identification of additional cases with bi-allelic null OBSCN variants will further delineate OBSCN-related disease and the clinical course of disease.
Collapse
Affiliation(s)
- Macarena Cabrera-Serrano
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre of Medical Research, University of Western Australia, Nedlands, WA, Australia
- Unidad de Enfermedades Neuromusculares. Servicio de Neurologia y Neurofisiologia. Hospital Virgen del Rocio, Sevilla, Spain
| | - Laure Caccavelli
- Inserm U1151, Institut Necker Enfants-Malades, Reference Center of Inherited Metabolic Diseases and MetabERN, Necker-Enfants-Malades Hospital, Paris University, Paris, France
| | - Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland and Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Anna Vihola
- Folkhälsan Research Center, Helsinki, Finland and Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Tampere Neuromuscular Center, Tampere University Hospital, Tampere, Finland
| | - Manu Jokela
- Neuromuscular Research Center, Department of Neurology, Tampere University and University Hospital, Tampere, Finland
- Neurocenter, Department of Neurology, Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Mridul Johari
- Folkhälsan Research Center, Helsinki, Finland and Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Thierry Capiod
- Inserm U1151, Institut Necker Enfants-Malades, Reference Center of Inherited Metabolic Diseases and MetabERN, Necker-Enfants-Malades Hospital, Paris University, Paris, France
| | - Marine Madrange
- Inserm U1151, Institut Necker Enfants-Malades, Reference Center of Inherited Metabolic Diseases and MetabERN, Necker-Enfants-Malades Hospital, Paris University, Paris, France
| | - Enrico Bugiardini
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, UK
| | - Stefen Brady
- Department of Neurology, Southmead Hospital, Bristol, UK
| | - Rosaline Quinlivan
- MRC Centre for Neuromuscular Diseases, University College Hospitals, London, UK
| | - Ashirwad Merve
- MRC Centre for Neuromuscular Diseases, University College Hospitals, London, UK
| | - Renata Scalco
- MRC Centre for Neuromuscular Diseases, University College Hospitals, London, UK
| | - David Hilton-Jones
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Henry Houlden
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, UK
| | | | - Serdar Ceylaner
- Intergen Genetic Diagnosis and Research Center, Ankara, Turkey
| | - Jerry Vockley
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rhonda L. Taylor
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre of Medical Research, University of Western Australia, Nedlands, WA, Australia
| | - Chiara Folland
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre of Medical Research, University of Western Australia, Nedlands, WA, Australia
| | - Aasta Kelly
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
| | - Hayley Goullee
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre of Medical Research, University of Western Australia, Nedlands, WA, Australia
| | - Emil Ylikallio
- Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
| | - Mari Auranen
- Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Henna Tyynismaa
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Finland and Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Tampere Neuromuscular Center, Tampere University Hospital, Tampere, Finland
| | - Alistair R. R. Forrest
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre of Medical Research, University of Western Australia, Nedlands, WA, Australia
| | - Mark R. Davis
- Department of Diagnostic Genomics, PathWest Laboratory Medicine WA, Nedlands, WA, Australia
| | - Drago Bratkovic
- Metabolic Clinic, Women and Children’s Hospital, North Adelaide, SA, Australia
| | - Nicholas Manton
- SA Pathology, Women and Children’s Hospital, North Adelaide, SA, Australia
| | - Thomas Robertson
- Anatomical Pathology, Queensland Pathology, Brisbane, Queensland, Australia
| | - Pamela McCombe
- Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
- Centre for Clinical Research, The University of Queensland Centre for Clinical Research, Brisbane, Queensland, Australia
| | - Nigel G. Laing
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre of Medical Research, University of Western Australia, Nedlands, WA, Australia
- Department of Diagnostic Genomics, PathWest Laboratory Medicine WA, Nedlands, WA, Australia
| | - Liza Phillips
- SA Pathology, Women and Children’s Hospital, North Adelaide, SA, Australia
- The University of Adelaide, Adelaide, SA, Australia
| | - Pascale de Lonlay
- Inserm U1151, Institut Necker Enfants-Malades, Reference Center of Inherited Metabolic Diseases and MetabERN, Necker-Enfants-Malades Hospital, Paris University, Paris, France
| | - Gianina Ravenscroft
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre of Medical Research, University of Western Australia, Nedlands, WA, Australia
| |
Collapse
|
14
|
Guardia T, Eason M, Kontrogianni-Konstantopoulos A. Obscurin: A multitasking giant in the fight against cancer. Biochim Biophys Acta Rev Cancer 2021; 1876:188567. [PMID: 34015411 PMCID: PMC8349851 DOI: 10.1016/j.bbcan.2021.188567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/03/2021] [Accepted: 05/11/2021] [Indexed: 12/19/2022]
Abstract
Giant obscurins (720-870 kDa), encoded by OBSCN, were originally discovered in striated muscles as cytoskeletal proteins with scaffolding and regulatory roles. Recently though, they have risen to the spotlight as key players in cancer development and progression. Herein, we provide a timely prudent synopsis of the expanse of OBSCN mutations across 16 cancer types. Given the extensive work on OBSCN's role in breast epithelium, we summarize functional studies implicating obscurins as potent tumor suppressors in breast cancer and delve into an in silico analysis of its mutational profile and epigenetic (de)regulation using different dataset platforms and sophisticated computational tools. Lastly, we formally describe the OBSCN-Antisense-RNA-1 gene, which belongs to the long non-coding RNA family and discuss its potential role in modulating OBSCN expression in breast cancer. Collectively, we highlight the escalating involvement of obscurins in cancer biology and outline novel potential mechanisms of OBSCN (de)regulation that warrant further investigation.
Collapse
Affiliation(s)
- Talia Guardia
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Matthew Eason
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Aikaterini Kontrogianni-Konstantopoulos
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center, USA.
| |
Collapse
|
15
|
Qiu J, Wu L, Chang Y, Sun H, Sun J. Alternative splicing transitions associate with emerging atrophy phenotype during denervation-induced skeletal muscle atrophy. J Cell Physiol 2021; 236:4496-4514. [PMID: 33319931 DOI: 10.1002/jcp.30167] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/23/2020] [Accepted: 11/05/2020] [Indexed: 12/25/2022]
Abstract
Alternative splicing (AS) presents a key posttranscriptional regulatory mechanism associated with numerous physiological processes. However, little is known about its role in skeletal muscle atrophy. In this study, we used a rat model of denervated skeletal muscle atrophy and performed RNA-sequencing to analyze transcriptome profiling of tibialis anterior muscle at multiple time points following denervation. We found that AS is a novel mechanism involving muscle atrophy, which is independent changes at the transcript level. Bioinformatics analysis further revealed that AS transitions are associated with the appearance of the atrophic phenotype. Moreover, we found that the inclusion of multiple highly conserved exons of Obscn markedly increased at 3 days after denervation. In addition, we confirmed that this newly transcript inhibited C2C12 cell proliferation and exacerbated myotube atrophy. Finally, our study revealed that a large number of RNA-binding proteins were upregulated when the atrophy phenotype appeared. Our data emphasize the importance of AS in this process.
Collapse
Affiliation(s)
- Jiaying Qiu
- Department of Prenatal Screening and Diagnosis Center, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Affiliated Maternity and Child Health Care Hospital of Nantong University, Nantong University, Nantong, Jiangsu, China
| | - Liucheng Wu
- Laboratory Animal Center, Nantong University, Nantong, China
| | - Yan Chang
- School of Life Sciences, Nantong University, Nantong, Jiangsu, China
| | - Hualin Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Junjie Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| |
Collapse
|
16
|
Fleming JR, Rani A, Kraft J, Zenker S, Börgeson E, Lange S. Exploring Obscurin and SPEG Kinase Biology. J Clin Med 2021; 10:jcm10050984. [PMID: 33801198 PMCID: PMC7957886 DOI: 10.3390/jcm10050984] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/10/2021] [Accepted: 02/18/2021] [Indexed: 12/15/2022] Open
Abstract
Three members of the obscurin protein family that contain tandem kinase domains with important signaling functions for cardiac and striated muscles are the giant protein obscurin, its obscurin-associated kinase splice isoform, and the striated muscle enriched protein kinase (SPEG). While there is increasing evidence for the specific roles that each individual kinase domain plays in cross-striated muscles, their biology and regulation remains enigmatic. Our present study focuses on kinase domain 1 and the adjacent low sequence complexity inter-kinase domain linker in obscurin and SPEG. Using Phos-tag gels, we show that the linker in obscurin contains several phosphorylation sites, while the same region in SPEG remained unphosphorylated. Our homology modeling, mutational analysis and molecular docking demonstrate that kinase 1 in obscurin harbors all key amino acids important for its catalytic function and that actions of this domain result in autophosphorylation of the protein. Our bioinformatics analyses also assign a list of putative substrates for kinase domain 1 in obscurin and SPEG, based on the known and our newly proposed phosphorylation sites in muscle proteins, including obscurin itself.
Collapse
Affiliation(s)
- Jennifer R. Fleming
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
- Correspondence: (J.R.F.); (E.B.); (S.L.)
| | - Alankrita Rani
- Centre for Molecular and Translational Medicine, The Wallenberg Laboratory and Wallenberg, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; (A.R.); (J.K.)
| | - Jamie Kraft
- Centre for Molecular and Translational Medicine, The Wallenberg Laboratory and Wallenberg, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; (A.R.); (J.K.)
| | - Sanja Zenker
- Department of Medicine, University of California, San Diego, CA 92093, USA;
| | - Emma Börgeson
- Centre for Molecular and Translational Medicine, The Wallenberg Laboratory and Wallenberg, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; (A.R.); (J.K.)
- Department of Clinical Physiology, Sahlgrenska University Hospital, 41345 Gothenburg, Sweden
- Correspondence: (J.R.F.); (E.B.); (S.L.)
| | - Stephan Lange
- Centre for Molecular and Translational Medicine, The Wallenberg Laboratory and Wallenberg, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; (A.R.); (J.K.)
- Department of Medicine, University of California, San Diego, CA 92093, USA;
- Correspondence: (J.R.F.); (E.B.); (S.L.)
| |
Collapse
|
17
|
Péladeau C, Jasmin BJ. Targeting IRES-dependent translation as a novel approach for treating Duchenne muscular dystrophy. RNA Biol 2020; 18:1238-1251. [PMID: 33164678 DOI: 10.1080/15476286.2020.1847894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Internal-ribosomal entry sites (IRES) are translational elements that allow the initiation machinery to start protein synthesis via internal initiation. IRESs promote tissue-specific translation in stress conditions when conventional cap-dependent translation is inhibited. Since many IRES-containing mRNAs are relevant to diseases, this cellular mechanism is emerging as an attractive therapeutic target for pharmacological and genetic modulations. Indeed, there has been growing interest over the past years in determining the therapeutic potential of IRESs for several disease conditions such as cancer, neurodegeneration and neuromuscular diseases including Duchenne muscular dystrophy (DMD). IRESs relevant for DMD have been identified in several transcripts whose protein product results in functional improvements in dystrophic muscles. Together, these converging lines of evidence indicate that activation of IRES-mediated translation of relevant transcripts in DMD muscle represents a novel and appropriate therapeutic strategy for DMD that warrants further investigation, particularly to identify agents that can modulate their activity.
Collapse
Affiliation(s)
- Christine Péladeau
- Department of Cellular and Molecular Medicine, and the Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, and the Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
18
|
Blondelle J, Biju A, Lange S. The Role of Cullin-RING Ligases in Striated Muscle Development, Function, and Disease. Int J Mol Sci 2020; 21:E7936. [PMID: 33114658 PMCID: PMC7672578 DOI: 10.3390/ijms21217936] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/11/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
The well-orchestrated turnover of proteins in cross-striated muscles is one of the fundamental processes required for muscle cell function and survival. Dysfunction of the intricate protein degradation machinery is often associated with development of cardiac and skeletal muscle myopathies. Most muscle proteins are degraded by the ubiquitin-proteasome system (UPS). The UPS involves a number of enzymes, including E3-ligases, which tightly control which protein substrates are marked for degradation by the proteasome. Recent data reveal that E3-ligases of the cullin family play more diverse and crucial roles in cross striated muscles than previously anticipated. This review highlights some of the findings on the multifaceted functions of cullin-RING E3-ligases, their substrate adapters, muscle protein substrates, and regulatory proteins, such as the Cop9 signalosome, for the development of cross striated muscles, and their roles in the etiology of myopathies.
Collapse
Affiliation(s)
- Jordan Blondelle
- Department of Medicine, University of California, La Jolla, CA 92093, USA
| | - Andrea Biju
- Department of Medicine, University of California, La Jolla, CA 92093, USA
| | - Stephan Lange
- Department of Medicine, University of California, La Jolla, CA 92093, USA
- Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden
| |
Collapse
|
19
|
Hu LYR, Kontrogianni-Konstantopoulos A. Proteomic Analysis of Myocardia Containing the Obscurin R4344Q Mutation Linked to Hypertrophic Cardiomyopathy. Front Physiol 2020; 11:478. [PMID: 32528308 PMCID: PMC7247546 DOI: 10.3389/fphys.2020.00478] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/20/2020] [Indexed: 12/25/2022] Open
Abstract
Obscurin is a giant cytoskeletal protein with structural and regulatory roles encoded by the OBSCN gene. Recently, mutations in OBSCN were associated with the development of different forms of cardiomyopathies, including hypertrophic cardiomyopathy (HCM). We previously reported that homozygous mice carrying the HCM-linked R4344Q obscurin mutation develop arrhythmia by 1-year of age under sedentary conditions characterized by increased heart rate, frequent incidents of premature ventricular contractions, and episodes of spontaneous ventricular tachycardia. In an effort to delineate the molecular mechanisms that contribute to the observed arrhythmic phenotype, we subjected protein lysates prepared from left ventricles of 1-year old R4344Q and wild-type mice to comparative proteomics analysis using tandem mass spectrometry; raw data are available via ProteomeXchange with identifier PXD017314. We found that the expression levels of proteins involved in cardiac function and disease, cytoskeletal organization, electropotential regulation, molecular transport and metabolism were significantly altered. Moreover, phospho-proteomic evaluation revealed changes in the phosphorylation profile of Ca2+ cycling proteins, including sAnk1.5, a major binding partner of obscurin localized in the sarcoplasmic reticulum; notably, this is the first report indicating that sAnk1 undergoes phosphorylation. Taken together, our findings implicate obscurin in diverse cellular processes within the myocardium, which is consistent with its multiple binding partners, localization in different subcellular compartments, and disease association.
Collapse
Affiliation(s)
- Li-Yen R Hu
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, United States
| | | |
Collapse
|
20
|
Calderon-Ospina CA, Hernández-Sómerson M, García AM, Mejia A, Tamayo-Agudelo C, Laissue P, Fonseca Mendoza DJ. A Pharmacogenomic Dissection of a Rosuvastatin-Induced Rhabdomyolysis Case Evokes the Polygenic Nature of Adverse Drug Reactions. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2020; 13:59-70. [PMID: 32184647 PMCID: PMC7060025 DOI: 10.2147/pgpm.s228709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 11/28/2019] [Indexed: 12/17/2022]
Abstract
Rosuvastatin, is a widely-used statin for the treatment of hypercholesterolemia and the prevention of cardiovascular diseases. Although rosuvastatin is well tolerated, about 3/10.000 patients can suffer severe myopathy. Rhabdomyolysis is a severe medical condition that causes injury to the skeletal muscle, electrolyte imbalances, acute renal failure and extreme creatine kinase (CK) elevation. Little is known regarding the molecular involvement of rosuvastatin-induced rhabdomyolysis (RIR). It has been demonstrated that genomic variants associated with decreased enzymatic activity of proteins are important determinants in plasmatic and skeletal muscle distribution of rosuvastatin and its toxicity. Until now, no interactions of ticagrelor, ezetimibe and rosuvastatin have been described with the consideration of pharmacogenomics predisposition. The present report involves a whole-exome sequencing (WES), in a patient affected by rosuvastatin-induced rhabdomyolysis. A pharmacogenomic dissection was performed by analyzing a comprehensive subset of candidate genes (n=160) potentially related to RIR. The genes were selected according to their implication in drug metabolism or inherited myopathies. Using an innovative approach of bioinformatics analysis, considering rare and common variants, we identified 19 genomic variations potentially related to the pharmacokinetic/pharmacodynamic modifications of rosuvastatin, ezetimibe and ticagrelor. The affected genes are involved in Phase I metabolism (CYP2C19, CYP2E1, CYP1A1, CYP2D6 and CYP2C9), Phase II metabolism (UGT2B15 and UGT2B7), influx transportation (SLCO1B3 and SLCO2B1), efflux transportation (ABCG8, ABCB11, ABCC4 and ABCB1), drug targeting (NPC1L1) and inherited myopathy etiology (OBSCN). We report three rare, potentially pathogenic molecular variants in CYP2C19, NPC1L1 and OBSCN genes. Pharmacogenetic analysis indicated that the patient was a carrier of inactivating alleles in several pharmacogenes involved in drug toxicity. The whole-exome sequencing and bioinformatics analysis presented here represents an innovative way to identify genomic variants contributing with RIR´s origin and evokes the polygenic nature of adverse drug reactions.
Collapse
Affiliation(s)
- Carlos Alberto Calderon-Ospina
- Center for Research in Genetics and Genomics-CIGGUR, GENIUROS Research Group, School of Medicine and Health Sciences. Universidad Del Rosario, Bogotá, Colombia
| | - Mario Hernández-Sómerson
- Medical Clinic Service, Hospital Universitario Mayor Méderi-Universidad Del Rosario, Bogotá, Colombia
| | - Ana María García
- Center for Research in Genetics and Genomics-CIGGUR, GENIUROS Research Group, School of Medicine and Health Sciences. Universidad Del Rosario, Bogotá, Colombia
| | - Adriana Mejia
- Center for Research in Genetics and Genomics-CIGGUR, GENIUROS Research Group, School of Medicine and Health Sciences. Universidad Del Rosario, Bogotá, Colombia
| | - Caroll Tamayo-Agudelo
- Center for Research in Genetics and Genomics-CIGGUR, GENIUROS Research Group, School of Medicine and Health Sciences. Universidad Del Rosario, Bogotá, Colombia
| | - Paul Laissue
- Center for Research in Genetics and Genomics-CIGGUR, GENIUROS Research Group, School of Medicine and Health Sciences. Universidad Del Rosario, Bogotá, Colombia
| | - Dora Janeth Fonseca Mendoza
- Center for Research in Genetics and Genomics-CIGGUR, GENIUROS Research Group, School of Medicine and Health Sciences. Universidad Del Rosario, Bogotá, Colombia
| |
Collapse
|
21
|
Lange S, Pinotsis N, Agarkova I, Ehler E. The M-band: The underestimated part of the sarcomere. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2020; 1867:118440. [PMID: 30738787 PMCID: PMC7023976 DOI: 10.1016/j.bbamcr.2019.02.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/16/2019] [Accepted: 02/05/2019] [Indexed: 12/20/2022]
Abstract
The sarcomere is the basic unit of the myofibrils, which mediate skeletal and cardiac Muscle contraction. Two transverse structures, the Z-disc and the M-band, anchor the thin (actin and associated proteins) and thick (myosin and associated proteins) filaments to the elastic filament system composed of titin. A plethora of proteins are known to be integral or associated proteins of the Z-disc and its structural and signalling role in muscle is better understood, while the molecular constituents of the M-band and its function are less well defined. Evidence discussed here suggests that the M-band is important for managing force imbalances during active muscle contraction. Its molecular composition is fine-tuned, especially as far as the structural linkers encoded by members of the myomesin family are concerned and depends on the specific mechanical characteristics of each particular muscle fibre type. Muscle activity signals from the M-band to the nucleus and affects transcription of sarcomeric genes, especially via serum response factor (SRF). Due to its important role as shock absorber in contracting muscle, the M-band is also more and more recognised as a contributor to muscle disease.
Collapse
Affiliation(s)
- Stephan Lange
- Biomedical Research Facility 2, School of Medicine, University of California, San Diego, Medical Sciences Research Bldg, 9500 Gilman Drive, La Jolla, CA 92093-0613C, USA; University of Gothenburg, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Gothenburg, Sweden
| | - Nikos Pinotsis
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Irina Agarkova
- InSphero, Wagistrasse 27, CH-8952 Schlieren, Switzerland
| | - Elisabeth Ehler
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK; School of Cardiovascular Medicine and Sciences, British Heart Foundation Research Excellence Centre, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK.
| |
Collapse
|
22
|
Pierantozzi E, Szentesi P, Al-Gaadi D, Oláh T, Dienes B, Sztretye M, Rossi D, Sorrentino V, Csernoch L. Calcium Homeostasis Is Modified in Skeletal Muscle Fibers of Small Ankyrin1 Knockout Mice. Int J Mol Sci 2019; 20:ijms20133361. [PMID: 31323924 PMCID: PMC6651408 DOI: 10.3390/ijms20133361] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/01/2019] [Accepted: 07/04/2019] [Indexed: 11/16/2022] Open
Abstract
Small Ankyrins (sAnk1) are muscle-specific isoforms generated by the Ank1 gene that participate in the organization of the sarcoplasmic reticulum (SR) of striated muscles. Accordingly, the volume of SR tubules localized around the myofibrils is strongly reduced in skeletal muscle fibers of 4- and 10-month-old sAnk1 knockout (KO) mice, while additional structural alterations only develop with aging. To verify whether the lack of sAnk1 also alters intracellular Ca2+ handling, cytosolic Ca2+ levels were analyzed in stimulated skeletal muscle fibers from 4- and 10-month-old sAnk1 KO mice. The SR Ca2+ content was reduced in sAnk1 KO mice regardless of age. The amplitude of the Ca2+ transients induced by depolarizing pulses was decreased in myofibers of sAnk1 KO with respect to wild type (WT) fibers, while their voltage dependence was not affected. Furthermore, analysis of spontaneous Ca2+ release events (sparks) on saponin-permeabilized muscle fibers indicated that the frequency of sparks was significantly lower in fibers from 4-month-old KO mice compared to WT. Furthermore, both the amplitude and spatial spread of sparks were significantly smaller in muscle fibers from both 4- and 10-month-old KO mice compared to WT. These data suggest that the absence of sAnk1 results in an impairment of SR Ca2+ release, likely as a consequence of a decreased Ca2+ store due to the reduction of the SR volume in sAnk1 KO muscle fibers.
Collapse
Affiliation(s)
- Enrico Pierantozzi
- Department of Molecular and Developmental Medicine, Molecular Medicine Section, University of Siena, 53100 Siena, Italy
| | - Péter Szentesi
- Department of Physiology, Medical Faculty, University of Debrecen, H-4002 Debrecen, Hungary
| | - Dána Al-Gaadi
- Department of Physiology, Medical Faculty, University of Debrecen, H-4002 Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, H-4002 Debrecen, Hungary
| | - Tamás Oláh
- Department of Physiology, Medical Faculty, University of Debrecen, H-4002 Debrecen, Hungary
| | - Beatrix Dienes
- Department of Physiology, Medical Faculty, University of Debrecen, H-4002 Debrecen, Hungary
| | - Mónika Sztretye
- Department of Physiology, Medical Faculty, University of Debrecen, H-4002 Debrecen, Hungary
| | - Daniela Rossi
- Department of Molecular and Developmental Medicine, Molecular Medicine Section, University of Siena, 53100 Siena, Italy
| | - Vincenzo Sorrentino
- Department of Molecular and Developmental Medicine, Molecular Medicine Section, University of Siena, 53100 Siena, Italy
| | - László Csernoch
- Department of Physiology, Medical Faculty, University of Debrecen, H-4002 Debrecen, Hungary.
| |
Collapse
|
23
|
Randazzo D, Khalique U, Belanto JJ, Kenea A, Talsness DM, Olthoff JT, Tran MD, Zaal KJ, Pak K, Pinal-Fernandez I, Mammen AL, Sackett D, Ervasti JM, Ralston E. Persistent upregulation of the β-tubulin tubb6, linked to muscle regeneration, is a source of microtubule disorganization in dystrophic muscle. Hum Mol Genet 2019; 28:1117-1135. [PMID: 30535187 DOI: 10.1093/hmg/ddy418] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/26/2018] [Accepted: 12/02/2018] [Indexed: 12/20/2022] Open
Abstract
In healthy adult skeletal muscle fibers microtubules form a three-dimensional grid-like network. In the mdx mouse, a model of Duchenne muscular dystrophy (DMD), microtubules are mostly disordered, without periodicity. These microtubule defects have been linked to the mdx mouse pathology. We now report that increased expression of the beta 6 class V β-tubulin (tubb6) contributes to the microtubule changes of mdx muscles. Wild-type muscle fibers overexpressing green fluorescent protein (GFP)-tubb6 (but not GFP-tubb5) have disorganized microtubules whereas mdx muscle fibers depleted of tubb6 (but not of tubb5) normalize their microtubules, suggesting that increasing tubb6 is toxic. However, tubb6 increases spontaneously during differentiation of mouse and human muscle cultures. Furthermore, endogenous tubb6 is not uniformly expressed in mdx muscles but is selectively increased in fiber clusters, which we identify as regenerating. Similarly, mdx-based rescued transgenic mice that retain a higher than expected tubb6 level show focal expression of tubb6 in subsets of fibers. Tubb6 is also upregulated in cardiotoxin-induced mouse muscle regeneration, in human myositis and DMD biopsies, and the tubb6 level correlates with that of embryonic myosin heavy chain, a regeneration marker. In conclusion, modulation of a β-tubulin isotype plays a role in muscle differentiation and regeneration. Increased tubb6 expression and microtubule reorganization are not pathological per se but reflect a return to an earlier developmental stage. However, chronic elevation of tubb6, as occurs in the mdx mouse, may contribute to the repeated cycles of regeneration and to the pathology of the disease.
Collapse
Affiliation(s)
- Davide Randazzo
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Umara Khalique
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Joseph J Belanto
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Aster Kenea
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Dana M Talsness
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - John T Olthoff
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Michelle D Tran
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Kristien J Zaal
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Katherine Pak
- Laboratory of Muscle Stem Cells and Gene Regulation, Muscle Disease Unit, NIAMS, NIH, Bethesda, MD, USA
| | - Iago Pinal-Fernandez
- Laboratory of Muscle Stem Cells and Gene Regulation, Muscle Disease Unit, NIAMS, NIH, Bethesda, MD, USA.,Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Andrew L Mammen
- Laboratory of Muscle Stem Cells and Gene Regulation, Muscle Disease Unit, NIAMS, NIH, Bethesda, MD, USA.,Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Dan Sackett
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), NIH, Bethesda, MD, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Evelyn Ralston
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| |
Collapse
|
24
|
Blondelle J, Marrocco V, Clark M, Desmond P, Myers S, Nguyen J, Wright M, Bremner S, Pierantozzi E, Ward S, Estève E, Sorrentino V, Ghassemian M, Lange S. Murine obscurin and Obsl1 have functionally redundant roles in sarcolemmal integrity, sarcoplasmic reticulum organization, and muscle metabolism. Commun Biol 2019; 2:178. [PMID: 31098411 PMCID: PMC6509138 DOI: 10.1038/s42003-019-0405-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 03/28/2019] [Indexed: 12/19/2022] Open
Abstract
Biological roles of obscurin and its close homolog Obsl1 (obscurin-like 1) have been enigmatic. While obscurin is highly expressed in striated muscles, Obsl1 is found ubiquitously. Accordingly, obscurin mutations have been linked to myopathies, whereas mutations in Obsl1 result in 3M-growth syndrome. To further study unique and redundant functions of these closely related proteins, we generated and characterized Obsl1 knockouts. Global Obsl1 knockouts are embryonically lethal. In contrast, skeletal muscle-specific Obsl1 knockouts show a benign phenotype similar to obscurin knockouts. Only deletion of both proteins and removal of their functional redundancy revealed their roles for sarcolemmal stability and sarcoplasmic reticulum organization. To gain unbiased insights into changes to the muscle proteome, we analyzed tibialis anterior and soleus muscles by mass spectrometry, uncovering additional changes to the muscle metabolism. Our analyses suggest that all obscurin protein family members play functions for muscle membrane systems.
Collapse
Affiliation(s)
- Jordan Blondelle
- Division of Cardiology, School of Medicine, University of California, San Diego, 92093 CA USA
| | - Valeria Marrocco
- Division of Cardiology, School of Medicine, University of California, San Diego, 92093 CA USA
| | - Madison Clark
- Division of Cardiology, School of Medicine, University of California, San Diego, 92093 CA USA
| | - Patrick Desmond
- Division of Cardiology, School of Medicine, University of California, San Diego, 92093 CA USA
| | - Stephanie Myers
- Division of Cardiology, School of Medicine, University of California, San Diego, 92093 CA USA
| | - Jim Nguyen
- Division of Cardiology, School of Medicine, University of California, San Diego, 92093 CA USA
| | - Matthew Wright
- Division of Cardiology, School of Medicine, University of California, San Diego, 92093 CA USA
| | - Shannon Bremner
- Department of Orthopedic Surgery, School of Medicine, University of California, San Diego, 92093 CA USA
| | - Enrico Pierantozzi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, 53100 Italy
| | - Samuel Ward
- Department of Orthopedic Surgery, School of Medicine, University of California, San Diego, 92093 CA USA
| | - Eric Estève
- Division of Cardiology, School of Medicine, University of California, San Diego, 92093 CA USA
- Université Grenoble Alpes, HP2, Grenoble, 38706 France
| | - Vincenzo Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, 53100 Italy
| | - Majid Ghassemian
- Department of Chemistry and Biochemistry, University of California, San Diego, 92093 CA USA
| | - Stephan Lange
- Division of Cardiology, School of Medicine, University of California, San Diego, 92093 CA USA
- Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, 413 45 Sweden
| |
Collapse
|
25
|
Grimes KM, Prasad V, McNamara JW. Supporting the heart: Functions of the cardiomyocyte's non-sarcomeric cytoskeleton. J Mol Cell Cardiol 2019; 131:187-196. [PMID: 30978342 DOI: 10.1016/j.yjmcc.2019.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 04/02/2019] [Accepted: 04/05/2019] [Indexed: 02/06/2023]
Abstract
The non-contractile cytoskeleton in cardiomyocytes is comprised of cytoplasmic actin, microtubules, and intermediate filaments. In addition to providing mechanical support to these cells, these structures are important effectors of tension-sensing and signal transduction and also provide networks for the transport of proteins and organelles. The majority of our knowledge on the function and structure of these cytoskeletal networks comes from research on proliferative cell types. However, in recent years, researchers have begun to show that there are important cardiomyocyte-specific functions of the cytoskeleton. Here we will discuss the current state of cytoskeletal biology in cardiomyocytes, as well as research from other cell types, that together suggest there is a wealth of knowledge on cardiac health and disease waiting to be uncovered through exploration of the complex signaling networks of cardiomyocyte non-sarcomeric cytoskeletal proteins.
Collapse
Affiliation(s)
- Kelly M Grimes
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
| | - Vikram Prasad
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - James W McNamara
- Heart, Lung and Vascular Institute, University of Cincinnati, Cincinnati, OH, USA
| |
Collapse
|
26
|
Nelson DM, Lindsay A, Judge LM, Duan D, Chamberlain JS, Lowe DA, Ervasti JM. Variable rescue of microtubule and physiological phenotypes in mdx muscle expressing different miniaturized dystrophins. Hum Mol Genet 2019; 27:2090-2100. [PMID: 29618008 DOI: 10.1093/hmg/ddy113] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 03/26/2018] [Indexed: 01/08/2023] Open
Abstract
Delivery of miniaturized dystrophin genes via adeno-associated viral vectors is one leading approach in development to treat Duchenne muscular dystrophy. Here we directly compared the functionality of five mini- and micro-dystrophins via skeletal muscle-specific transgenic expression in dystrophin-deficient mdx mice. We evaluated their ability to rescue defects in the microtubule network, passive stiffness and contractility of skeletal muscle. Transgenic mdx mice expressing the short dystrophin isoform Dp116 served as a negative control. All mini- and micro-dystrophins restored elevated detyrosinated α-tubulin and microtubule density of mdx muscle to values not different from C57BL/10, however, only mini-dystrophins restored the transverse component of the microtubule lattice back to C57BL/10. Passive stiffness values in mdx muscles expressing mini- or micro-dystrophins were not different from C57BL/10. While all mini- and micro-dystrophins conferred significant protection from eccentric contraction-induced force loss in vivo and ex vivo compared to mdx, removal of repeats two and three resulted in less protection from force drop caused by eccentric contraction ex vivo. Our data reveal subtle yet significant differences in the relative functionalities for different therapeutic constructs of miniaturized dystrophin in terms of protection from ex vivo eccentric contraction-induced force loss and restoration of an organized microtubule lattice.
Collapse
Affiliation(s)
- D'anna M Nelson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Angus Lindsay
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.,Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Luke M Judge
- Department of Neurology, University of Washington, Seattle, WA 98195, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, MO 65212, USA
| | | | - Dawn A Lowe
- Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| |
Collapse
|
27
|
Whitley JA, Ex-Willey AM, Marzolf DR, Ackermann MA, Tongen AL, Kokhan O, Wright NT. Obscurin is a semi-flexible molecule in solution. Protein Sci 2019; 28:717-726. [PMID: 30666746 DOI: 10.1002/pro.3578] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 01/14/2019] [Indexed: 01/10/2023]
Abstract
Obscurin, a giant modular cytoskeletal protein, is comprised mostly of tandem immunoglobulin-like (Ig-like) domains. This architecture allows obscurin to connect distal targets within the cell. The linkers connecting the Ig domains are usually short (3-4 residues). The physical effect arising from these short linkers is not known; such linkers may lead to a stiff elongated molecule or, conversely, may lead to a more compact and dynamic structure. In an effort to better understand how linkers affect obscurin flexibility, and to better understand the physical underpinnings of this flexibility, here we study the structure and dynamics of four representative sets of dual obscurin Ig domains using experimental and computational techniques. We find in all cases tested that tandem obscurin Ig domains interact at the poles of each domain and tend to stay relatively extended in solution. NMR, SAXS, and MD simulations reveal that while tandem domains are elongated, they also bend and flex significantly. By applying this behavior to a simplified model, it becomes apparent obscurin can link targets more than 200 nm away. However, as targets get further apart, obscurin begins acting as a spring and requires progressively more energy to further elongate.
Collapse
Affiliation(s)
- Jacob A Whitley
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| | - Aidan M Ex-Willey
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807.,Department of Physiology and Cell Biology, Wexner Medical Center, Ohio State University, Columbus, Ohio, 43210
| | - Daniel R Marzolf
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| | - Maegen A Ackermann
- Department of Physiology and Cell Biology, Wexner Medical Center, Ohio State University, Columbus, Ohio, 43210
| | - Anthony L Tongen
- Department of Mathematics and Statistics, James Madison University, Harrisonburg, Virginia, 22807
| | - Oleksandr Kokhan
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| | - Nathan T Wright
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| |
Collapse
|
28
|
Grogan A, Kontrogianni-Konstantopoulos A. Unraveling obscurins in heart disease. Pflugers Arch 2018; 471:735-743. [PMID: 30099631 DOI: 10.1007/s00424-018-2191-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 08/01/2018] [Indexed: 12/18/2022]
Abstract
Obscurins, expressed from the single OBSCN gene, are a family of giant, modular, cytoskeletal proteins that play key structural and regulatory roles in striated muscles. They were first implicated in the development of heart disease in 2007 when two missense mutations were found in a patient diagnosed with hypertrophic cardiomyopathy (HCM). Since then, the discovery of over a dozen missense, frameshift, and splicing mutations that are linked to various forms of cardiomyopathy, including HCM, dilated cardiomyopathy (DCM), and left ventricular non-compaction (LVNC), has highlighted OBSCN as a potential disease-causing gene. At this time, the functional consequences of the identified mutations remain largely elusive, and much work has yet to be done to characterize the disease mechanisms of pathological OBSCN variants. Herein, we describe the OBSCN mutations known to date, discuss their potential impact on disease development, and provide future directions in order to better understand the involvement of obscurins in heart disease.
Collapse
Affiliation(s)
- Alyssa Grogan
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene St., Baltimore, MD, 21201, USA
| | | |
Collapse
|
29
|
Gonorazky HD, Bönnemann CG, Dowling JJ. The genetics of congenital myopathies. HANDBOOK OF CLINICAL NEUROLOGY 2018; 148:549-564. [PMID: 29478600 DOI: 10.1016/b978-0-444-64076-5.00036-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Congenital myopathies are a clinically and genetically heterogeneous group of conditions that most commonly present at or around the time of birth with hypotonia, muscle weakness, and (often) respiratory distress. Historically, this group of disorders has been subclassified based on muscle histopathologic characteristics. There has been an explosion of gene discovery, and there are now at least 32 different genetic causes of disease. With this increased understanding of the genetic basis of disease has come the knowledge that the mutations in congenital myopathy genes can present with a wide variety of clinical phenotypes and can result in a broad spectrum of histopathologic findings on muscle biopsy. In addition, mutations in several genes can share the same histopathologic features. The identification of new genes and interpretation of different pathomechanisms at a molecular level have helped us to understand the clinical and histopathologic similarities that this group of disorders share. In this review, we highlight the genetic understanding for each subtype, its pathogenesis, and the future key issues in congenital myopathies.
Collapse
Affiliation(s)
- Hernan D Gonorazky
- Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, United States
| | - James J Dowling
- Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada.
| |
Collapse
|
30
|
Wang L, Geist J, Grogan A, Hu LYR, Kontrogianni-Konstantopoulos A. Thick Filament Protein Network, Functions, and Disease Association. Compr Physiol 2018; 8:631-709. [PMID: 29687901 PMCID: PMC6404781 DOI: 10.1002/cphy.c170023] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sarcomeres consist of highly ordered arrays of thick myosin and thin actin filaments along with accessory proteins. Thick filaments occupy the center of sarcomeres where they partially overlap with thin filaments. The sliding of thick filaments past thin filaments is a highly regulated process that occurs in an ATP-dependent manner driving muscle contraction. In addition to myosin that makes up the backbone of the thick filament, four other proteins which are intimately bound to the thick filament, myosin binding protein-C, titin, myomesin, and obscurin play important structural and regulatory roles. Consistent with this, mutations in the respective genes have been associated with idiopathic and congenital forms of skeletal and cardiac myopathies. In this review, we aim to summarize our current knowledge on the molecular structure, subcellular localization, interacting partners, function, modulation via posttranslational modifications, and disease involvement of these five major proteins that comprise the thick filament of striated muscle cells. © 2018 American Physiological Society. Compr Physiol 8:631-709, 2018.
Collapse
Affiliation(s)
- Li Wang
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Janelle Geist
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Alyssa Grogan
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Li-Yen R. Hu
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | | |
Collapse
|
31
|
Belanto JJ, Olthoff JT, Mader TL, Chamberlain CM, Nelson DM, McCourt PM, Talsness DM, Gundersen GG, Lowe DA, Ervasti JM. Independent variability of microtubule perturbations associated with dystrophinopathy. Hum Mol Genet 2018; 25:4951-4961. [PMID: 28171583 DOI: 10.1093/hmg/ddw318] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/15/2016] [Accepted: 09/12/2016] [Indexed: 11/14/2022] Open
Abstract
Absence of the protein dystrophin causes Duchenne muscular dystrophy. Dystrophin directly binds to microtubules in vitro, and its absence in vivo correlates with disorganization of the subsarcolemmal microtubule lattice, increased detyrosination of α-tubulin, and altered redox signaling. We previously demonstrated that the dystrophin homologue utrophin neither binds microtubules in vitro nor rescues microtubule lattice organization when overexpressed in muscles of dystrophin-deficient mdx mice. Here, we fine-mapped the dystrophin domain necessary for microtubule binding to spectrin-like repeats 20–22. We show that transgenic mdx mice expressing a full-length dystrophin/utrophin chimera completely lacking microtubule binding activity are surprisingly rescued for all measured dystrophic phenotypes, including full restoration of microtubule lattice organization. Conversely, despite the presence of dystrophin at the sarcolemma, β-sarcoglycan-deficient skeletal muscle presents with a disorganized and densified microtubule lattice. Finally, we show that the levels of α-tubulin detyrosination remain significantly elevated to that of mdx levels in transgenic mdx mice expressing nearly full-length dystrophin. Our results demonstrate that the microtubule-associated perturbations of mdx muscle are distinct, separable, and can vary independently from other parameters previously ascribed to dystrophin deficiency.
Collapse
Affiliation(s)
- Joseph J Belanto
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - John T Olthoff
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Tara L Mader
- Programs in Rehabilitation Science and Physical Therapy, Department of Physical Medicine and Rehabilitation, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Christopher M Chamberlain
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - D'anna M Nelson
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Preston M McCourt
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Dana M Talsness
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Gregg G Gundersen
- Department of Pathology & Cell Biology, Columbia University, New York, NY, USA
| | - Dawn A Lowe
- Programs in Rehabilitation Science and Physical Therapy, Department of Physical Medicine and Rehabilitation, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| |
Collapse
|
32
|
Rossi D, Palmio J, Evilä A, Galli L, Barone V, Caldwell TA, Policke RA, Aldkheil E, Berndsen CE, Wright NT, Malfatti E, Brochier G, Pierantozzi E, Jordanova A, Guergueltcheva V, Romero NB, Hackman P, Eymard B, Udd B, Sorrentino V. A novel FLNC frameshift and an OBSCN variant in a family with distal muscular dystrophy. PLoS One 2017; 12:e0186642. [PMID: 29073160 PMCID: PMC5657976 DOI: 10.1371/journal.pone.0186642] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 10/04/2017] [Indexed: 11/30/2022] Open
Abstract
A novel FLNC c.5161delG (p.Gly1722ValfsTer61) mutation was identified in two members of a French family affected by distal myopathy and in one healthy relative. This FLNC c.5161delG mutation is one nucleotide away from a previously reported FLNC mutation (c.5160delC) that was identified in patients and in asymptomatic carriers of three Bulgarian families with distal muscular dystrophy, indicating a low penetrance of the FLNC frameshift mutations. Given these similarities, we believe that the two FLNC mutations alone can be causative of distal myopathy without full penetrance. Moreover, comparative analysis of the clinical manifestations indicates that patients of the French family show an earlier onset and a complete segregation of the disease. As a possible explanation of this, the two French patients also carry a OBSCN c.13330C>T (p.Arg4444Trp) mutation. The p.Arg4444Trp variant is localized within the OBSCN Ig59 domain that, together with Ig58, binds to the ZIg9/ZIg10 domains of titin at Z-disks. Structural and functional studies indicate that this OBSCN p.Arg4444Trp mutation decreases titin binding by ~15-fold. On this line, we suggest that the combination of the OBSCN p.Arg4444Trp variant and of the FLNC c.5161delG mutation, can cooperatively affect myofibril stability and increase the penetrance of muscular dystrophy in the French family.
Collapse
Affiliation(s)
- Daniela Rossi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena and Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Johanna Palmio
- Neuromuscular Research Center, Tampere University and University Hospital, Tampere, Finland
| | - Anni Evilä
- Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Lucia Galli
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena and Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Virginia Barone
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena and Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Tracy A. Caldwell
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, United States of America
| | - Rachel A. Policke
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, United States of America
| | - Esraa Aldkheil
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, United States of America
| | - Christopher E. Berndsen
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, United States of America
| | - Nathan T. Wright
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, United States of America
| | - Edoardo Malfatti
- Neuromuscular Morphology Unit, and Reference Center for Neuromuscular Diseases, Myology Institute, Groupe Hospitalier La Pitié-Salpêtrière, Paris, France
| | - Guy Brochier
- Neuromuscular Morphology Unit, and Reference Center for Neuromuscular Diseases, Myology Institute, Groupe Hospitalier La Pitié-Salpêtrière, Paris, France
| | - Enrico Pierantozzi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena and Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Albena Jordanova
- Molecular Neurogenomics Group, University of Antwerp, Antwerp, Belgium
- Molecular Medicine Center, Department of Medical Chemistry and Biochemistry, Medical University-Sofia, Sofia, Bulgaria
| | | | - Norma Beatriz Romero
- Neuromuscular Morphology Unit, and Reference Center for Neuromuscular Diseases, Myology Institute, Groupe Hospitalier La Pitié-Salpêtrière, Paris, France
| | - Peter Hackman
- Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Bruno Eymard
- Neuromuscular Morphology Unit, and Reference Center for Neuromuscular Diseases, Myology Institute, Groupe Hospitalier La Pitié-Salpêtrière, Paris, France
| | - Bjarne Udd
- Neuromuscular Research Center, Tampere University and University Hospital, Tampere, Finland
- Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
- Department of Neurology, Vaasa Central Hospital, Vaasa, Finland
| | - Vincenzo Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena and Azienda Ospedaliera Universitaria Senese, Siena, Italy
- * E-mail:
| |
Collapse
|
33
|
Randazzo D, Pierantozzi E, Rossi D, Sorrentino V. The potential of obscurin as a therapeutic target in muscle disorders. Expert Opin Ther Targets 2017; 21:897-910. [DOI: 10.1080/14728222.2017.1361931] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Davide Randazzo
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda
| | - Enrico Pierantozzi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Daniela Rossi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Vincenzo Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| |
Collapse
|
34
|
Pette D. What Can be Learned from the Time Course of Changes in Low-Frequency Stimulated Muscle? Eur J Transl Myol 2017; 27:6723. [PMID: 28713537 PMCID: PMC5505094 DOI: 10.4081/ejtm.2017.6723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Not available.
Collapse
Affiliation(s)
- Dirk Pette
- Department of Biology, University of Konstanz, Germany
| |
Collapse
|
35
|
Hu LYR, Ackermann MA, Hecker PA, Prosser BL, King B, O’Connell KA, Grogan A, Meyer LC, Berndsen CE, Wright NT, Jonathan Lederer W, Kontrogianni-Konstantopoulos A. Deregulated Ca 2+ cycling underlies the development of arrhythmia and heart disease due to mutant obscurin. SCIENCE ADVANCES 2017; 3:e1603081. [PMID: 28630914 PMCID: PMC5462502 DOI: 10.1126/sciadv.1603081] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/17/2017] [Indexed: 05/05/2023]
Abstract
Obscurins are cytoskeletal proteins with structural and regulatory roles encoded by OBSCN. Mutations in OBSCN are associated with the development of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Specifically, the R4344Q mutation present in immunoglobulin domain 58 (Ig58) was the first to be linked with the development of HCM. To assess the effects of R4344Q in vivo, we generated the respective knock-in mouse model. Mutant obscurins are expressed and incorporated normally into sarcomeres. The expression patterns of sarcomeric and Ca2+-cycling proteins are unaltered in sedentary 1-year-old knock-in myocardia, with the exception of sarco/endoplasmic reticulum Ca2+ adenosine triphosphatase 2 (SERCA2) and pentameric phospholamban whose levels are significantly increased and decreased, respectively. Isolated cardiomyocytes from 1-year-old knock-in hearts exhibit increased Ca2+-transients and Ca2+-load in the sarcoplasmic reticulum and faster contractility kinetics. Moreover, sedentary 1-year-old knock-in animals develop tachycardia accompanied by premature ventricular contractions, whereas 2-month-old knock-in animals subjected to pressure overload develop a DCM-like phenotype. Structural analysis revealed that the R4344Q mutation alters the distribution of electrostatic charges over the Ig58 surface, thus interfering with its binding capabilities. Consistent with this, wild-type Ig58 interacts with phospholamban modestly, and this interaction is markedly enhanced in the presence of R4344Q. Together, our studies demonstrate that under sedentary conditions, the R4344Q mutation results in Ca2+ deregulation and spontaneous arrhythmia, whereas in the presence of chronic, pathological stress, it leads to cardiac remodeling and dilation. We postulate that enhanced binding between mutant obscurins and phospholamban leads to SERCA2 disinhibition, which may underlie the observed pathological alterations.
Collapse
Affiliation(s)
- Li-Yen R. Hu
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - Maegen A. Ackermann
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - Peter A. Hecker
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - Benjamin L. Prosser
- Department of Physiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Physiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Brendan King
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - Kelly A. O’Connell
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - Alyssa Grogan
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Baltimore, MD 21201, USA
| | - Logan C. Meyer
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA
| | - Christopher E. Berndsen
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA
| | - Nathan T. Wright
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA
| | - W. Jonathan Lederer
- Department of Physiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | |
Collapse
|
36
|
Manring HR, Carter OA, Ackermann MA. Obscure functions: the location-function relationship of obscurins. Biophys Rev 2017; 9:245-258. [PMID: 28510116 DOI: 10.1007/s12551-017-0254-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 03/05/2017] [Indexed: 12/18/2022] Open
Abstract
The obscurin family of polypeptides is essential for normal striated muscle function and contributes to the pathogenesis of fatal diseases, including cardiomyopathies and cancers. The single mammalian obscurin gene, OBSCN, gives rise to giant (∼800 kDa) and smaller (∼40-500 kDa) proteins that are composed of tandem adhesion and signaling motifs. Mammalian obscurin proteins are expressed in a variety of cell types, including striated muscles, and localize to distinct subcellular compartments where they contribute to diverse cellular processes. Obscurin homologs in Caenorhabditis elegans and Drosophila possess a similar domain architecture and are also expressed in striated muscles. The long sought after question, "what does obscurin do?" is complex and cannot be addressed without taking into consideration the subcellular distribution of these proteins and local isoform concentration. Herein, we present an overview of the functions of obscurins and begin to define the intricate relationship between their subcellular distributions and functions in striated muscles.
Collapse
Affiliation(s)
- Heather R Manring
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA
| | - Olivia A Carter
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA
| | - Maegen A Ackermann
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA. .,Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA.
| |
Collapse
|
37
|
Abstract
Striated cardiac and skeletal muscles play very different roles in the body, but they are similar at the molecular level. In particular, contraction, regardless of the type of muscle, is a precise and complex process involving the integral protein myofilaments and their associated regulatory components. The smallest functional unit of muscle contraction is the sarcomere. Within the sarcomere can be found a sophisticated ensemble of proteins associated with the thick filaments (myosin, myosin binding protein-C, titin, and obscurin) and thin myofilaments (actin, troponin, tropomyosin, nebulin, and nebulette). These parallel thick and thin filaments slide across one another, pulling the two ends of the sarcomere together to regulate contraction. More specifically, the regulation of both timing and force of contraction is accomplished through an intricate network of intra- and interfilament interactions belonging to each myofilament. This review introduces the sarcomere proteins involved in striated muscle contraction and places greater emphasis on the more recently identified and less well-characterized myofilaments: cardiac myosin binding protein-C, titin, nebulin, and obscurin. © 2017 American Physiological Society. Compr Physiol 7:675-692, 2017.
Collapse
Affiliation(s)
- Brian Leei Lin
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA
| | - Taejeong Song
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA.,Department of Internal Medicine, Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Sciences, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Sakthivel Sadayappan
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA.,Department of Internal Medicine, Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Sciences, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| |
Collapse
|
38
|
Pernigo S, Fukuzawa A, Beedle AEM, Holt M, Round A, Pandini A, Garcia-Manyes S, Gautel M, Steiner RA. Binding of Myomesin to Obscurin-Like-1 at the Muscle M-Band Provides a Strategy for Isoform-Specific Mechanical Protection. Structure 2016; 25:107-120. [PMID: 27989621 PMCID: PMC5222588 DOI: 10.1016/j.str.2016.11.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/16/2016] [Accepted: 11/18/2016] [Indexed: 12/03/2022]
Abstract
The sarcomeric cytoskeleton is a network of modular proteins that integrate mechanical and signaling roles. Obscurin, or its homolog obscurin-like-1, bridges the giant ruler titin and the myosin crosslinker myomesin at the M-band. Yet, the molecular mechanisms underlying the physical obscurin(-like-1):myomesin connection, important for mechanical integrity of the M-band, remained elusive. Here, using a combination of structural, cellular, and single-molecule force spectroscopy techniques, we decode the architectural and functional determinants defining the obscurin(-like-1):myomesin complex. The crystal structure reveals a trans-complementation mechanism whereby an incomplete immunoglobulin-like domain assimilates an isoform-specific myomesin interdomain sequence. Crucially, this unconventional architecture provides mechanical stability up to forces of ∼135 pN. A cellular competition assay in neonatal rat cardiomyocytes validates the complex and provides the rationale for the isoform specificity of the interaction. Altogether, our results reveal a novel binding strategy in sarcomere assembly, which might have implications on muscle nanomechanics and overall M-band organization. The structure of the human obscurin-like-1:myomesin complex has been determined A myomesin sequence complements an immunoglobulin fold of obscurin-like-1 This binding mechanism provides mechanical stability up to forces of ∼135 pN Possible implications on muscle nanomechanics and M-band organization are discussed
Collapse
Affiliation(s)
- Stefano Pernigo
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Atsushi Fukuzawa
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Cardiovascular Division, King's College London BHF Centre of Research Excellence, London SE1 1UL, UK
| | - Amy E M Beedle
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Department of Physics, King's College London, London WC2R 2LS, UK
| | - Mark Holt
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Cardiovascular Division, King's College London BHF Centre of Research Excellence, London SE1 1UL, UK
| | - Adam Round
- European Molecular Biology Laboratory, Grenoble Outstation, 38042 Grenoble, France; School of Chemical and Physical Sciences, Keele University, Keele, Staffordshire, UK
| | - Alessandro Pandini
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Department of Computer Science and Synthetic Biology Theme, Brunel University London, London UB8 3PH, UK
| | - Sergi Garcia-Manyes
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Department of Physics, King's College London, London WC2R 2LS, UK.
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Cardiovascular Division, King's College London BHF Centre of Research Excellence, London SE1 1UL, UK.
| | - Roberto A Steiner
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK.
| |
Collapse
|
39
|
Randazzo D, Blaauw B, Paolini C, Pierantozzi E, Spinozzi S, Lange S, Chen J, Protasi F, Reggiani C, Sorrentino V. Exercise-induced alterations and loss of sarcomeric M-line organization in the diaphragm muscle of obscurin knockout mice. Am J Physiol Cell Physiol 2016; 312:C16-C28. [PMID: 27784675 DOI: 10.1152/ajpcell.00098.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 10/25/2016] [Indexed: 11/22/2022]
Abstract
We recently reported that skeletal muscle fibers of obscurin knockout (KO) mice present altered distribution of ankyrin B (ankB), disorganization of the subsarcolemmal microtubules, and reduced localization of dystrophin at costameres. In addition, these mice have impaired running endurance and increased exercise-induced sarcolemmal damage compared with wild-type animals. Here, we report results from a combined approach of physiological, morphological, and structural studies in which we further characterize the skeletal muscles of obscurin KO mice. A detailed examination of exercise performance, using different running protocols, revealed that the reduced endurance of obscurin KO animals on the treadmill depends on exercise intensity and age. Indeed, a mild running protocol did not evidence significant differences between control and obscurin KO mice, whereas comparison of running abilities of 2-, 6-, and 11-mo-old mice exercised at exhaustion revealed a progressive age-dependent reduction of the exercise tolerance in KO mice. Histological analysis indicated that heavy exercise induced leukocyte infiltration, fibrotic connective tissue deposition, and hypercontractures in the diaphragm of KO mice. On the same line, electron microscopy revealed that, in the diaphragm of exercised obscurin KO mice, but not in the hindlimb muscles, both M-line and H-zone of sarcomeres appeared wavy and less defined. Altogether, these results suggest that obscurin is required for the maintenance of morphological and ultrastructural integrity of skeletal muscle fibers against damage induced by intense mechanical stress and point to the diaphragm as the skeletal muscle most severely affected in obscurin-deficient mice.
Collapse
Affiliation(s)
- D Randazzo
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - B Blaauw
- Venetian Institute of Molecular Medicine, Padua, Italy.,Interuniversity Institute of Myology
| | - C Paolini
- Center for Research on Ageing and Translational Medicine & Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti, Chieti, Italy.,Interuniversity Institute of Myology
| | - E Pierantozzi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - S Spinozzi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - S Lange
- University of California, San Diego School of Medicine, San Diego, California
| | - J Chen
- University of California, San Diego School of Medicine, San Diego, California
| | - F Protasi
- Center for Research on Ageing and Translational Medicine & Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti, Chieti, Italy.,Interuniversity Institute of Myology
| | - C Reggiani
- Department of Biomedical Sciences, University of Padua, Padua, Italy; and.,Interuniversity Institute of Myology
| | - V Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy; .,Interuniversity Institute of Myology
| |
Collapse
|
40
|
Yan R, Lai S, Yang Y, Shi H, Cai Z, Sorrentino V, Du H, Chen H. A novel type 2 diabetes risk allele increases the promoter activity of the muscle-specific small ankyrin 1 gene. Sci Rep 2016; 6:25105. [PMID: 27121283 PMCID: PMC4848520 DOI: 10.1038/srep25105] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 04/08/2016] [Indexed: 11/09/2022] Open
Abstract
Genome-wide association studies have identified Ankyrin-1 (ANK1) as a common type 2 diabetes (T2D) susceptibility locus. However, the underlying causal variants and functional mechanisms remain unknown. We screened for 8 tag single nucleotide polymorphisms (SNPs) in ANK1 between 2 case-control studies. Genotype analysis revealed significant associations of 3 SNPs, rs508419 (first identified here), rs515071, and rs516946 with T2D (P < 0.001). These SNPs were in linkage disequilibrium (r2 > 0.80); subsequent analysis indicated that the CCC haplotype associated with increased T2D susceptibility (OR 1.447, P < 0.001). Further mapping showed that rs508419 resides in the muscle-specific ANK1 gene promoter. Allele-specific mRNA and protein level measurements confirmed association of the C allele with increased small ANK1 (sAnk1) expression in human skeletal muscle (P = 0.018 and P < 0.001, respectively). Luciferase assays showed increased rs508419-C allele transcriptional activity in murine skeletal muscle C2C12 myoblasts, and electrophoretic mobility-shift assays demonstrated altered rs508419 DNA-protein complex formation. Glucose uptake was decreased with excess sAnk1 expression upon insulin stimulation. Thus, the ANK1 rs508419-C T2D-risk allele alters DNA-protein complex binding leading to increased promoter activity and sAnk1 expression; thus, increased sAnk1 expression in skeletal muscle might contribute to T2D susceptibility.
Collapse
Affiliation(s)
- Rengna Yan
- School of Medicine, Nanjing University, Nanjing, 210093, China.,Department of Endocrinology, Jinling Hospital Affiliated to Nanjing University School of Medicine, Nanjing, 210002, China.,Department of Endocrinology, Nanjing First Hospital Affiliated to Nanjing Medical University, Nanjing, 210006, China
| | - Shanshan Lai
- School of Medicine, Nanjing University, Nanjing, 210093, China.,MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center and the School of Medicine, Nanjing University, National Resource Center for Mutant Mice, Nanjing 210093, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing, 210002, China
| | - Yang Yang
- School of Medicine, Nanjing University, Nanjing, 210093, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing, 210002, China.,Department of Urology, Drum Tower Hospital Affiliated to Nanjing University School of Medicine, Nanjing, 210008, China
| | - Hongfei Shi
- School of Medicine, Nanjing University, Nanjing, 210093, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing, 210002, China.,Department of Orthopedics, Drum Tower Hospital Affiliated to Nanjing University School of Medicine, Nanjing, 210008, China
| | - Zhenming Cai
- School of Medicine, Nanjing University, Nanjing, 210093, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing, 210002, China
| | - Vincenzo Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, 53100, Italy
| | - Hong Du
- School of Medicine, Nanjing University, Nanjing, 210093, China.,Department of Endocrinology, Jinling Hospital Affiliated to Nanjing University School of Medicine, Nanjing, 210002, China
| | - Huimei Chen
- School of Medicine, Nanjing University, Nanjing, 210093, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing, 210002, China
| |
Collapse
|
41
|
Editors T. Muscle Decline in Aging and Neuromuscular Disorders - Mechanisms and Countermeasures: Terme Euganee, Padova (Italy), April 13-16, 2016. Eur J Transl Myol 2016; 26:5904. [PMID: 27054021 PMCID: PMC4821223 DOI: 10.4081/ejtm.2016.5904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Not available.
Collapse
|
42
|
Organization of junctional sarcoplasmic reticulum proteins in skeletal muscle fibers. J Muscle Res Cell Motil 2015; 36:501-15. [DOI: 10.1007/s10974-015-9421-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/08/2015] [Indexed: 01/24/2023]
|
43
|
Wu HC, Yamankurt G, Luo J, Subramaniam J, Hashmi SS, Hu H, Cunha SR. Identification and characterization of two ankyrin-B isoforms in mammalian heart. Cardiovasc Res 2015; 107:466-77. [PMID: 26109584 DOI: 10.1093/cvr/cvv184] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 06/17/2015] [Indexed: 11/13/2022] Open
Abstract
AIMS Excitation-contraction coupling in cardiomyocytes requires the proper targeting and retention of membrane proteins to unique domains by adaptor proteins like ankyrin-B. While ankyrin-B has been shown to interact with a variety of membrane and structural proteins located at different subcellular domains in cardiomyocytes, what regulates the specificity of ankyrin-B for particular interacting proteins remains elusive. METHODS AND RESULTS Here, we report the identification of two novel ankyrin-B isoforms AnkB-188 and AnkB-212 in human, rat, and mouse hearts. Novel cDNAs for both isoforms were isolated by long-range PCR of reverse-transcribed mRNA isolated from human ventricular tissue. The isoforms can be discriminated based on their function and subcellular distribution in cardiomyocytes. Heterologous overexpression of AnkB-188 increases sodium-calcium exchanger (NCX) membrane expression and current, while selective knockdown of AnkB-188 in cardiomyocytes reduces NCX expression and localization in addition to causing irregular contraction rhythms. Using an isoform-specific antibody, we demonstrate that the expression of AnkB-212 is restricted to striated muscles and is localized to the M-line of cardiomyocytes by interacting with obscurin. Selective knockdown of AnkB-212 significantly attenuates the expression of endogenous ankyrin-B at the M-line but does not disrupt NCX expression at transverse tubules in cardiomyocytes. CONCLUSION The identification and characterization of two functionally distinct ankyrin-B isoforms in heart provide compelling evidence that alternative splicing of the ANK2 gene regulates the fidelity of ankyrin-B interactions with proteins.
Collapse
Affiliation(s)
- Henry C Wu
- Department of Integrative Biology and Pharmacology, The University of Texas Medical School at Houston, 6431 Fannin Street, MSE R331, Houston, TX 77030, USA
| | - Gokay Yamankurt
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - JiaLie Luo
- Department of Anesthesiology, the Center for the Study of Itch, Washington University Pain Center, Washington University School of Medicine in St Louis, St Louis, MO 63110, USA
| | - Janani Subramaniam
- Department of Integrative Biology and Pharmacology, The University of Texas Medical School at Houston, 6431 Fannin Street, MSE R331, Houston, TX 77030, USA
| | - Syed Shahrukh Hashmi
- Department of Pediatrics, The University of Texas Medical School at Houston, Houston, TX 77030, USA
| | - Hongzhen Hu
- Department of Anesthesiology, the Center for the Study of Itch, Washington University Pain Center, Washington University School of Medicine in St Louis, St Louis, MO 63110, USA
| | - Shane R Cunha
- Department of Integrative Biology and Pharmacology, The University of Texas Medical School at Houston, 6431 Fannin Street, MSE R331, Houston, TX 77030, USA
| |
Collapse
|
44
|
Miller NLG, Kleinschmidt EG, Schlaepfer DD. RhoGEFs in cell motility: novel links between Rgnef and focal adhesion kinase. Curr Mol Med 2014; 14:221-34. [PMID: 24467206 DOI: 10.2174/1566524014666140128110339] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Revised: 07/08/2013] [Accepted: 12/02/2013] [Indexed: 11/22/2022]
Abstract
Rho guanine exchange factors (GEFs) are a large, diverse family of proteins defined by their ability to catalyze the exchange of GDP for GTP on small GTPase proteins such as Rho family members. GEFs act as integrators from varied intra- and extracellular sources to promote spatiotemporal activity of Rho GTPases that control signaling pathways regulating cell proliferation and movement. Here we review recent studies elucidating roles of RhoGEF proteins in cell motility. Emphasis is placed on Dbl-family GEFs and connections to development, integrin signaling to Rho GTPases regulating cell adhesion and movement, and how these signals may enhance tumor progression. Moreover, RhoGEFs have additional domains that confer distinctive functions or specificity. We will focus on a unique interaction between Rgnef (also termed Arhgef28 or p190RhoGEF) and focal adhesion kinase (FAK), a non-receptor tyrosine kinase that controls migration properties of normal and tumor cells. This Rgnef-FAK interaction activates canonical GEF-dependent RhoA GTPase activity to govern contractility and also functions as a scaffold in a GEF-independent manner to enhance FAK activation. Recent studies have also brought to light the importance of specific regions within the Rgnef pleckstrin homology (PH) domain for targeting the membrane. As revealed by ongoing Rgnef-FAK investigations, exploring GEF roles in cancer will yield fundamental new information on the molecular mechanisms promoting tumor spread and metastasis.
Collapse
Affiliation(s)
| | | | - D D Schlaepfer
- University of California San Diego, Moores Cancer Center, Department of Reproductive Medicine, MC 0803, 3855 Health Sciences Dr., La Jolla, CA 92093 USA.
| |
Collapse
|
45
|
Neto OA, Tassy O, Biancalana V, Zanoteli E, Pourquié O, Laporte J. Integrative data mining highlights candidate genes for monogenic myopathies. PLoS One 2014; 9:e110888. [PMID: 25353622 PMCID: PMC4213015 DOI: 10.1371/journal.pone.0110888] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 09/18/2014] [Indexed: 11/25/2022] Open
Abstract
Inherited myopathies are a heterogeneous group of disabling disorders with still barely understood pathological mechanisms. Around 40% of afflicted patients remain without a molecular diagnosis after exclusion of known genes. The advent of high-throughput sequencing has opened avenues to the discovery of new implicated genes, but a working list of prioritized candidate genes is necessary to deal with the complexity of analyzing large-scale sequencing data. Here we used an integrative data mining strategy to analyze the genetic network linked to myopathies, derive specific signatures for inherited myopathy and related disorders, and identify and rank candidate genes for these groups. Training sets of genes were selected after literature review and used in Manteia, a public web-based data mining system, to extract disease group signatures in the form of enriched descriptor terms, which include functional annotation, human and mouse phenotypes, as well as biological pathways and protein interactions. These specific signatures were then used as an input to mine and rank candidate genes, followed by filtration against skeletal muscle expression and association with known diseases. Signatures and identified candidate genes highlight both potential common pathological mechanisms and allelic disease groups. Recent discoveries of gene associations to diseases, like B3GALNT2, GMPPB and B3GNT1 to congenital muscular dystrophies, were prioritized in the ranked lists, suggesting a posteriori validation of our approach and predictions. We show an example of how the ranked lists can be used to help analyze high-throughput sequencing data to identify candidate genes, and highlight the best candidate genes matching genomic regions linked to myopathies without known causative genes. This strategy can be automatized to generate fresh candidate gene lists, which help cope with database annotation updates as new knowledge is incorporated.
Collapse
Affiliation(s)
- Osorio Abath Neto
- Dept. of Translational Medicine and Neurogenetics, IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, Collège de France, Illkirch, Strasbourg, France
- Departamento de Neurologia, Faculdade de Medicina de São Paulo (FMUSP), São Paulo, Brazil
| | - Olivier Tassy
- Dept. of Development & Stem Cells, IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, Collège de France, Illkirch, Strasbourg, France
| | - Valérie Biancalana
- Dept. of Translational Medicine and Neurogenetics, IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, Collège de France, Illkirch, Strasbourg, France
- Faculté de Médecine, Laboratoire de Diagnostic Génétique, Nouvel Hopital Civil, Strasbourg, France
| | - Edmar Zanoteli
- Departamento de Neurologia, Faculdade de Medicina de São Paulo (FMUSP), São Paulo, Brazil
| | - Olivier Pourquié
- Dept. of Development & Stem Cells, IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, Collège de France, Illkirch, Strasbourg, France
| | - Jocelyn Laporte
- Dept. of Translational Medicine and Neurogenetics, IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, Collège de France, Illkirch, Strasbourg, France
| |
Collapse
|
46
|
Giacomello E, Quarta M, Paolini C, Squecco R, Fusco P, Toniolo L, Blaauw B, Formoso L, Rossi D, Birkenmeier C, Peters LL, Francini F, Protasi F, Reggiani C, Sorrentino V. Deletion of small ankyrin 1 (sAnk1) isoforms results in structural and functional alterations in aging skeletal muscle fibers. Am J Physiol Cell Physiol 2014; 308:C123-38. [PMID: 25354526 DOI: 10.1152/ajpcell.00090.2014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Muscle-specific ankyrins 1 (sAnk1) are a group of small ankyrin 1 isoforms, of which sAnk1.5 is the most abundant. sAnk1 are localized in the sarcoplasmic reticulum (SR) membrane from where they interact with obscurin, a myofibrillar protein. This interaction appears to contribute to stabilize the SR close to the myofibrils. Here we report the structural and functional characterization of skeletal muscles from sAnk1 knockout mice (KO). Deletion of sAnk1 did not change the expression and localization of SR proteins in 4- to 6-mo-old sAnk1 KO mice. Structurally, the main modification observed in skeletal muscles of adult sAnk1 KO mice (4-6 mo of age) was the reduction of SR volume at the sarcomere A band level. With increasing age (at 12-15 mo of age) extensor digitorum longus (EDL) skeletal muscles of sAnk1 KO mice develop prematurely large tubular aggregates, whereas diaphragm undergoes significant structural damage. Parallel functional studies revealed specific changes in the contractile performance of muscles from sAnk1 KO mice and a reduced exercise tolerance in an endurance test on treadmill compared with control mice. Moreover, reduced Qγ charge and L-type Ca(2+) current, which are indexes of affected excitation-contraction coupling, were observed in diaphragm fibers from 12- to 15-mo-old mice, but not in other skeletal muscles from sAnk1 KO mice. Altogether, these findings show that the ablation of sAnk1, by altering the organization of the SR, renders skeletal muscles susceptible to undergo structural and functional alterations more evident with age, and point to an important contribution of sAnk1 to the maintenance of the longitudinal SR architecture.
Collapse
Affiliation(s)
- E Giacomello
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy; IIM-Interuniversity Institute of Myology
| | - M Quarta
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - C Paolini
- Ce.S.I., Center for Research on Ageing and Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio, Chieti, Italy; IIM-Interuniversity Institute of Myology
| | - R Squecco
- Department of Experimental and Clinical Medicine, University of Florence, Florence Italy; IIM-Interuniversity Institute of Myology
| | - P Fusco
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - L Toniolo
- Department of Biomedical Sciences, University of Padova, Padua, Italy; IIM-Interuniversity Institute of Myology
| | - B Blaauw
- Department of Biomedical Sciences, University of Padova, Padua, Italy; IIM-Interuniversity Institute of Myology; Venetian Institute of Molecular Medicine, Padua, Italy
| | - L Formoso
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - D Rossi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy; IIM-Interuniversity Institute of Myology
| | | | | | - F Francini
- Department of Experimental and Clinical Medicine, University of Florence, Florence Italy; IIM-Interuniversity Institute of Myology
| | - F Protasi
- Ce.S.I., Center for Research on Ageing and Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio, Chieti, Italy; IIM-Interuniversity Institute of Myology
| | - C Reggiani
- Department of Biomedical Sciences, University of Padova, Padua, Italy; IIM-Interuniversity Institute of Myology; CNR-Neuroscience Institute, Padua, Italy; and
| | - V Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy; IIM-Interuniversity Institute of Myology;
| |
Collapse
|
47
|
Vassilopoulos S, Gentil C, Lainé J, Buclez PO, Franck A, Ferry A, Précigout G, Roth R, Heuser JE, Brodsky FM, Garcia L, Bonne G, Voit T, Piétri-Rouxel F, Bitoun M. Actin scaffolding by clathrin heavy chain is required for skeletal muscle sarcomere organization. ACTA ACUST UNITED AC 2014; 205:377-93. [PMID: 24798732 PMCID: PMC4018784 DOI: 10.1083/jcb.201309096] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Clathrin heavy chain contributes to the formation and maintenance of the contractile apparatus in skeletal muscle through interactions with costameric proteins. The ubiquitous clathrin heavy chain (CHC), the main component of clathrin-coated vesicles, is well characterized for its role in intracellular membrane traffic and endocytosis from the plasma membrane (PM). Here, we demonstrate that in skeletal muscle CHC regulates the formation and maintenance of PM–sarcomere attachment sites also known as costameres. We show that clathrin forms large coated lattices associated with actin filaments and the muscle-specific isoform of α-actinin at the PM of differentiated myotubes. Depletion of CHC in myotubes induced a loss of actin and α-actinin sarcomeric organization, whereas CHC depletion in vivo induced a loss of contractile force due to the detachment of sarcomeres from the PM. Our results suggest that CHC contributes to the formation and maintenance of the contractile apparatus through interactions with costameric proteins and highlight an unconventional role for CHC in skeletal muscle that may be relevant to pathophysiology of neuromuscular disorders.
Collapse
Affiliation(s)
- Stéphane Vassilopoulos
- Institut National de la Santé et de la Recherche Médicale (INSERM) U974, 2 Centre National de la Recherche Scientifique (CNRS) UMR 7215, and 3 Université Pierre et Marie Curie-Paris 6, UM 76, Paris F-75013, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
Dystrophin and utrophin are highly similar proteins that both link cortical actin filaments with a complex of sarcolemmal glycoproteins, yet localize to different subcellular domains within normal muscle cells. In mdx mice and Duchenne muscular dystrophy patients, dystrophin is lacking and utrophin is consequently up-regulated and redistributed to locations normally occupied by dystrophin. Transgenic overexpression of utrophin has been shown to significantly improve aspects of the disease phenotype in the mdx mouse; therefore, utrophin up-regulation is under intense investigation as a potential therapy for Duchenne muscular dystrophy. Here we biochemically compared the previously documented microtubule binding activity of dystrophin with utrophin and analyzed several transgenic mouse models to identify phenotypes of the mdx mouse that remain despite transgenic utrophin overexpression. Our in vitro analyses revealed that dystrophin binds microtubules with high affinity and pauses microtubule polymerization, whereas utrophin has no activity in either assay. We also found that transgenic utrophin overexpression does not correct subsarcolemmal microtubule lattice disorganization, loss of torque production after in vivo eccentric contractions, or physical inactivity after mild exercise. Finally, our data suggest that exercise-induced inactivity correlates with loss of sarcolemmal neuronal NOS localization in mdx muscle, whereas loss of in vivo torque production after eccentric contraction-induced injury is associated with microtubule lattice disorganization.
Collapse
|
49
|
Obscurins: Goliaths and Davids take over non-muscle tissues. PLoS One 2014; 9:e88162. [PMID: 24516603 PMCID: PMC3916441 DOI: 10.1371/journal.pone.0088162] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 01/03/2014] [Indexed: 12/11/2022] Open
Abstract
Obscurins comprise a family of proteins originally identified in striated muscles, where they play essential roles in myofibrillogenesis, cytoskeletal organization, and Ca2+ homeostasis. They are encoded by the single OBSCN gene, and are composed of tandem adhesion domains and signaling motifs. To date, two giant obscurin isoforms have been described in detail that differ only at the extreme COOH-terminus; while obscurin-A (∼720 kDa) contains a non-modular COOH-terminus that harbors binding sites for the adaptor proteins ankyrins, obscurin-B (∼870 kDa) contains two COOH-terminal serine-threonine kinase domains preceded by adhesion motifs. Besides the two known giant obscurins, a thorough search of transcript databases suggests that complex alternative splicing of the obscurin transcript results in the generation of additional giant as well as small isoforms with molecular masses ranging between ∼50–970 kDa. These novel isoforms share common domains with the characterized isoforms, but also contain unique regions. Using a panel of highly specific antibodies directed against epitopes spanning the entire length of giant obscurins, we employed western blotting and immunohistochemistry to perform a systematic and comprehensive characterization of the expression profile of obscurins in muscle and non-muscle tissues. Our studies demonstrate for the first time that obscurins are not restricted to striated muscles, but are abundantly expressed in several tissues and organs including brain, skin, kidney, liver, spleen, and lung. While some obscurin isoforms are ubiquitously expressed, others are preferentially present in specific tissues and organs. Moreover, obscurins are present in select structures and cell types where they assume nuclear, cytosolic, and membrane distributions. Given the ubiquitous expression of some obscurins, along with the preferential expression of others, it becomes apparent that obscurins may play common and unique roles, respectively, in the regulation and maintenance of cell homeostasis in various tissues and organs throughout the body.
Collapse
|
50
|
Abstract
Giant muscle proteins (e.g., titin, nebulin, and obscurin) play a seminal role in muscle elasticity, stretch response, and sarcomeric organization. Each giant protein consists of multiple tandem structural domains, usually arranged in a modular fashion spanning 500 kDa to 4 MDa. Although many of the domains are similar in structure, subtle differences create a unique function of each domain. Recent high and low resolution structural and dynamic studies now suggest more nuanced overall protein structures than previously realized. These findings show that atomic structure, interactions between tandem domains, and intrasarcomeric environment all influence the shape, motion, and therefore function of giant proteins. In this article we will review the current understanding of titin, obscurin, and nebulin structure, from the atomic level through the molecular level.
Collapse
Affiliation(s)
- Logan C Meyer
- Department of Chemistry and Biochemistry, James Madison University Harrisonburg, VA, USA
| | - Nathan T Wright
- Department of Chemistry and Biochemistry, James Madison University Harrisonburg, VA, USA
| |
Collapse
|